test: known-answer coverage for HD derivation and the vault (closes #159)

wallet.js and vault.js — the two modules that hold user funds — had no
derivation or encryption tests. Add them, pinned to published vectors
rather than to whatever the implementation returns today.

wallet.js: hdWalletFromMnemonic, hdWalletFromXprv, deriveAddressFromXpub
and getSignerForAddress are pinned to the standard development recovery
phrase's first three accounts at m/44'/60'/0'/0/n and to the BIP-39
all-zero-entropy phrase's first address; addressFromPrivateKey is pinned
to the published key/address pairs, so the HD path and the bare-key path
must meet at the same address from two directions. isValidMnemonic and
isValidXprv cover bad checksum, wrong word count, wrong key type and
empty/garbage input. The absolute-vs-relative path asymmetry between
hdWalletFromMnemonic and hdWalletFromXprv is proven harmless: for the
same master key both reach the same xpub and the same addresses.

vault.js: round trip (including non-ASCII and an empty password), wrong
password rejected as a rejected promise with no partial plaintext,
tampered ciphertext / auth tag / nonce / salt rejected, truncated and
spliced blobs rejected, missing fields rejected, fresh salt and nonce per
encryption, the documented { salt, nonce, ciphertext } shape, and no
trace of the plaintext or password anywhere in the serialized blob. The
Argon2id cost parameters are pinned three ways — the INTERACTIVE
constants still mean 2 passes over 64 MiB, a key independently derived at
that cost opens the vault, and both encrypt and decrypt are observed
calling crypto_pwhash with those constants — because the KDF cost is the
vault's only defence against offline attack on a stolen blob and nothing
else in the suite would notice it being lowered. The tamper cases share
one encrypted fixture to stay inside script/test's 30-second budget.

One test is skipped: isValidXprv accepts an extended private key with a
one-character typo, because ethers skips base58 checksum verification for
the usual 82-byte payload. That defect is tracked separately and is not
fixed here; the skipped test asserts the correct behaviour and cites the
issue.

README.md

@@ -271,10 +271,10 @@ on a different table knows exactly tf I am talking about.
 
 Every interactive element must visually indicate that it is clickable. Buttons
 use a visible border, padding, and a hover state (invert to white-on-black).
-Text that triggers an action (e.g. "Import private key") uses an underline. No
+Text that triggers an action (e.g. "Add additional wallet...") uses an
-invisible hit targets, no bare text that happens to have a click handler. If it
+underline. No invisible hit targets, no bare text that happens to have a click
-does something when you click it, it must look like it does something when you
+handler. If it does something when you click it, it must look like it does
-click it.
+something when you click it.
 
 #### Display Consistency
 
@@ -334,115 +334,181 @@ attack.
 
 The core hierarchy is **Wallets → Addresses**:
 
-- A **wallet** is either:
+- A **wallet** is one of three types:
-    - An **HD wallet** (recovery phrase): generates multiple addresses from a
+    - An **HD wallet** (`type: "hd"`, recovery phrase): generates multiple
-      single 12/24 word recovery phrase using BIP-39/BIP-44 derivation. The user
+      addresses from a single 12/24 word recovery phrase using BIP-39/BIP-44
-      can add more addresses with a "+" button.
+      derivation. The user can add more addresses with a "+" button.
-    - A **key wallet** (private key): a single address imported directly from a
+    - A **key wallet** (`type: "key"`, private key): a single address imported
-      private key. No "+" button since there is only one address.
+      directly from a private key. No "+" button since there is only one
-- An **address** holds ETH and any user-added ERC-20 tokens.
+      address.
+    - An **xprv wallet** (`type: "xprv"`, extended private key): the same
+      multi-address behavior as an HD wallet, including the "+" button and the
+      address scan on import, but imported from an extended private key rather
+      than a recovery phrase. It therefore has no recovery phrase to display or
+      back up.
+- An **address** holds ETH and ERC-20 tokens.
 - The user can have multiple wallets, each with multiple addresses (HD) or a
   single address (key).
 
+Which tokens an address shows is decided by `fetchTokenBalances()` in
+`src/shared/balances.js`, from the Blockscout `token-balances` response, so
+tokens do appear without the user adding them. An ERC-20 is shown when its
+balance is nonzero and it is in the bundled top-250 token list, is tracked by
+the user, or has 1,000 or more holders; a token claiming a symbol from the
+bundled list from any other contract address is always dropped. That filter is
+unconditional — the "Hide tokens with fewer than 1,000 holders" setting governs
+the transaction history and the send-screen token selector, not this list.
+Tracked tokens with a zero balance are listed as well while "Show tracked tokens
+with zero balance" is on.
+
 #### Navigation
 
 The main view shows all addresses grouped by wallet, with ETH balances inline.
 The user taps an address to see its detail view (full address, balance, tokens,
-send/receive). Navigation is flat — every view has a "Back" or "Cancel" button
+send/receive). Navigation is a stack: each forward action pushes the current
-that returns to the previous context. No deep nesting, no tabs, no hamburger
+screen, and every view has a "Back" or "Cancel" button that pops back to it (see
-menus.
+the Screen Map below). There is no hamburger menu and no persistent tab bar; the
+Settings gear in the title bar is the only global control. Two screens carry an
+in-screen control beyond that: AddWallet uses three tabs to select the import
+mode, and AddressDetail keeps its one rarely-used action ("Export Private Key")
+behind a "···" menu.
 
 ### Screen Map
 
-Navigation uses a stack model (like iOS): each action pushes a screen onto the
+Navigation uses a stack model (like iOS): each forward action pushes the current
-stack, and "Back" pops it. The root screen is either Welcome (no wallets) or
+screen onto `state.viewStack`, and "Back" pops it (`pushCurrentView()` and
-Home (has wallets). Screens are listed below with their elements and
+`goBack()` in `src/popup/views/helpers.js`). The root screen is either Welcome
-transitions.
+(no wallets) or Home (has wallets). Each screen below gives its view id in
+parentheses; the registry of view ids is the `VIEWS` array in
+`src/popup/views/helpers.js`, and the markup for a screen is the element with id
+`view-` plus that view id in `src/popup/index.html`.
 
-#### Welcome
+Three elements sit outside the screens and are present on all of them: the title
+bar ("AutistMask by @sneak" plus the Settings gear), the flash message line
+under it, and the red banner at the very top that appears on a debug build, when
+runtime debug mode is on, or when the active network is a testnet. They are not
+repeated in the element lists below.
 
-- **When**: No wallets exist yet.
+Closing and reopening the popup returns to the screen the user was last on only
-- **Elements**: "AutistMask" heading, brief intro text, "Add wallet" button.
+for the views listed in `RESTORABLE_VIEWS` (`src/popup/index.js`). Every other
+screen, including ExportPrivKey, falls back to Home.
+
+#### Welcome (`welcome`)
+
+- **When**: No wallets exist yet (`state.hasWallet` is false). This is the root
+  screen in that case.
+- **Elements**:
+    - "Welcome! To get started, add a wallet." text
+    - "Add wallet" button
 - **Transitions**:
     - "Add wallet" → **AddWallet**
 
-#### Home
+#### Home (`main`)
 
 - **When**: At least one wallet exists. This is the root screen.
 - **Elements**:
-    - Header: "AutistMask", Settings gear button
+    - Active address ETH balance (large) + USD value in parentheses
-    - Active address ETH balance (large) + USD value (inline parentheses)
+    - "Total:" USD value across ETH and every token shown for the active address
-    - Total USD value across all tokens (small text)
     - Active address (color dot, full address, etherscan link, tap to copy)
-    - Send / Receive quick-action buttons
+    - Send / Receive quick-action buttons, both acting on the active address
     - ETH/USD price display
-    - Wallet list: each wallet shows name (tap to rename), "+" button (HD only),
+    - Wallet list: each wallet shows its name (tap to rename inline) and a "+"
-      and its addresses with color dots, balances, and `[info]` buttons
+      button for HD and xprv wallets, then one block per address with "Address
-    - Recent transactions across all addresses (merged, deduplicated, filtered)
+      N" (bold when active), the ENS name if resolved, the full address, an
+      `[info]` button, the address USD total, and a balance line for ETH and for
+      each token shown for that address
+    - "Recent Transactions": up to 25 transactions merged across every address
+      of every wallet, deduplicated by hash and filtered
     - "Add additional wallet..." link at bottom
 - **Transitions**:
-    - Tap address row → sets active address (no screen change)
+    - Tap address row → sets the active address and broadcasts
+      `AUTISTMASK_ACTIVE_CHANGED` (no screen change)
+    - Tap wallet name → inline rename field (no screen change)
+    - "+" on wallet → derives the next address inline (no screen change)
     - `[info]` on address → **AddressDetail**
-    - "Send" → **Send** (selects active address)
+    - "Send" → **Send** (refuses with a flash message on a zero balance)
     - "Receive" → **Receive** (shows active address QR)
-    - "+" on wallet → derives next address inline
+    - Tap home tx row → **TransactionDetail**
     - "Add additional wallet..." → **AddWallet**
     - Settings gear → **Settings** (toggles; tap again to return)
-    - Tap home tx row → **AddressDetail** (for the address involved)
 
-#### AddWallet
+#### AddWallet (`add-wallet`)
 
-- **When**: User wants to add a new wallet (from Home, Welcome, or Settings).
+- **When**: User wants to add a new wallet (from Welcome, Home, or Settings).
+  This one screen covers all three import modes; there is no separate import
+  screen.
 - **Elements**:
-    - "Add Wallet" heading, "Back" button
+    - "Back" button, "Add Wallet" heading
-    - Instruction text
+    - Three tabs — "From Phrase" (`tab-mnemonic`), "From Key" (`tab-privkey`),
-    - Die button `[die]` (generates random recovery phrase)
+      "From xprv" (`tab-xprv`) — each showing its own form section:
-    - Recovery phrase textarea
+        - **From Phrase**: instruction text, a die button that generates a
-    - Backup warning box (shown after die is clicked)
+          random recovery phrase, a recovery phrase textarea, and a backup
-    - Password + confirm password inputs
+          warning box that becomes visible once the die button has been used
-    - "Add" button
+        - **From Key**: instruction text and a masked private key input
-    - "Have a private key instead?" link
+        - **From xprv**: instruction text and a masked extended private key
-- **Transitions**:
+          input
-    - "Add" (valid phrase + password) → **Home**
+    - Password + confirm password inputs, with a hint line whose wording depends
-    - "Back" → previous screen (Home or Welcome)
+      on the selected tab
-    - "Have a private key instead?" → **ImportKey**
-
-#### ImportKey
-
-- **When**: User wants to import a single private key.
-- **Elements**:
-    - "Import Private Key" heading, "Back" button
-    - Instruction text
-    - Private key input (password-masked)
-    - Password + confirm password inputs
     - "Import" button
 - **Transitions**:
-    - "Import" (valid key + password) → **Home**
+    - "Import" with a valid entry and a matching password of at least 12
-    - "Back" → **AddWallet**
+      characters → creates the wallet, clears the navigation stack, and →
+      **Home**. The phrase and xprv modes then scan for further used addresses
+      and report the count as a flash message.
+    - "Import" with an invalid entry, a duplicate wallet or address, or a short
+      or mismatched password → flash message, no screen change
+    - "Back" → previous screen (Welcome, Home, or Settings)
 
-#### AddressDetail
+#### AddressDetail (`address`)
 
 - **When**: User tapped `[info]` on an address from Home.
 - **Elements**:
     - "Back" button
     - Blockie identicon (48px, centered)
     - Title: "Wallet Name — Address N"
-    - ENS name (if resolved, bold with color dot)
+    - ENS name (if resolved, bold above the address)
     - Full address (color dot, etherscan link, tap to copy)
     - USD total for address
-    - Balance list: ETH + tracked ERC-20 tokens (4 decimal places, USD inline).
+    - Balance list: ETH + the ERC-20 tokens shown for this address (4 decimal
-      Each balance row is clickable → **AddressToken**
+      places, USD inline). Each balance row is clickable → **AddressToken**
-    - Send / Receive / + Token buttons
+    - Send / Receive / + Token buttons and a "···" menu button
+    - "···" dropdown containing a single "Export Private Key" entry
     - Transaction list (with ENS resolution for counterparties)
 - **Transitions**:
     - Tap balance row → **AddressToken** (for that token)
-    - "Send" → **Send**
+    - "Send" → **Send** (refuses with a flash message on a zero balance)
     - "Receive" → **Receive**
     - "+ Token" → **AddToken**
+    - "···" → "Export Private Key" → **ExportPrivKey**
     - Tap transaction row → **TransactionDetail**
-    - "Back" → **Home**
+    - "Back" → previous screen (Home)
 
-#### AddressToken
+#### ExportPrivKey (`export-privkey`)
+
+- **When**: User chose "Export Private Key" from the "···" menu on
+  AddressDetail. This screen discloses secret material.
+- **Elements**:
+    - "Back" button
+    - Blockie identicon (48px, centered)
+    - "Export Private Key" heading
+    - "Wallet Name — Address N" and the full address (etherscan link, tap to
+      copy)
+    - Warning that anyone holding the private key can transfer all funds from
+      the address
+    - Error line
+    - Password input and "Reveal" button, shown until the key is revealed
+    - The private key on a highlighted background, tap to copy, shown only after
+      the password has been accepted
+- **Transitions**:
+    - "Reveal" (correct password) → decrypts the wallet secret, derives this
+      address's key, hides the password input and shows the key (no screen
+      change)
+    - "Reveal" (wrong password) → "Wrong password." on the error line, nothing
+      revealed
+    - "Back" → clears the key and password from the DOM, then → previous screen
+      (AddressDetail)
+
+#### AddressToken (`address-token`)
 
 - **When**: User clicked a specific token balance on AddressDetail.
 - **Elements**:
@@ -453,49 +519,64 @@ transitions.
     - USD total for this token
     - Single token balance line (4 decimal places)
     - Send / Receive buttons
+    - Token contract well (ERC-20 only): full contract address (tap to copy,
+      etherscan link) plus name, symbol, decimals, holder count and project
+      website where known
     - Token-filtered transaction list (only this token's transfers)
 - **Transitions**:
-    - "Send" → **Send** (token pre-selected and locked in dropdown)
+    - "Send" → **Send** (token locked: the dropdown is replaced by a static
+      symbol and contract address)
     - "Receive" → **Receive** (ERC-20 warning shown for non-ETH tokens)
     - Tap transaction row → **TransactionDetail**
-    - "Back" → **AddressDetail**
+    - "Back" → previous screen (AddressDetail)
 
-#### Send
+#### Send (`send`)
 
-- **When**: User wants to send ETH or a token from this address.
+- **When**: User wants to send ETH or a token, from Home, AddressDetail, or
+  AddressToken.
 - **Elements**:
-    - "Send" heading, "Back" button
+    - "Back" button, "Send" heading
     - From: address with color dot + etherscan link
     - What to send: token dropdown (or static display with contract address when
       locked from AddressToken)
-    - To: address or ENS name input
+    - To: address or ENS name input, with an inline validation message
     - Amount input with current balance display
-    - "Review" button
+    - "Review" button, disabled until the recipient validates
 - **Transitions**:
     - "Review" (valid inputs, ENS resolved) → **ConfirmTx**
-    - "Back" → **AddressToken** (if came from token view) or **AddressDetail**
+    - "Review" with an unresolvable ENS name or an invalid amount → flash
+      message, no screen change
+    - "Back" → previous screen (Home, AddressDetail, or AddressToken)
 
-#### ConfirmTx
+#### ConfirmTx (`confirm-tx`)
 
 - **When**: User reviewed send details and is ready to authorize.
 - **Elements**:
-    - "Confirm Transaction" heading, "Back" button
+    - "Back" button, "Confirm Transaction" heading
     - Type: "Native ETH transfer" or "ERC-20 token transfer (SYMBOL)"
     - Token contract: full address + etherscan link (ERC-20 only)
     - From: blockie + color dot + full address + etherscan link + wallet title
     - To: blockie + color dot + full address + etherscan link + ENS name
     - Amount: value + symbol (USD in parentheses)
     - Your balance: value + symbol (USD in parentheses)
-    - Estimated network fee: ETH amount (USD in parentheses), fetched async
+    - Estimated network fee: "Estimating..." then the ETH amount (USD in
-    - Warnings (scam address, self-send)
+      parentheses) or "Unable to estimate", fetched async
+    - Warnings: inline warnings from the local checks (scam address, self-send)
+      plus four reserved warning boxes made visible by the async checks —
+      recipient with no transaction history, recipient is a contract, burn
+      address, and an Etherscan phishing/scam label
     - Errors (insufficient balance)
-    - "Send" button (disabled if errors)
+    - Password: an inline field on this screen, not a modal, with its own error
+      line
+    - "Sign & Send" button (disabled if errors)
 - **Transitions**:
-    - "Send" → password modal → broadcast tx → **WaitTx**
+    - "Sign & Send" (correct password) → broadcast tx → **WaitTx**
-    - "Send" → password modal → broadcast fails → **ErrorTx**
+    - "Sign & Send" (correct password) → broadcast fails → **ErrorTx**
+    - "Sign & Send" (wrong password) → "Wrong password." on the password error
+      line, no screen change
     - "Back" → **Send**
 
-#### WaitTx
+#### WaitTx (`wait-tx`)
 
 - **When**: Transaction has been broadcast, waiting for on-chain confirmation.
 - **Elements**:
@@ -509,20 +590,24 @@ transitions.
     - Receipt found → **SuccessTx**
     - 60 seconds without confirmation → **ErrorTx** (timeout message)
 
-#### SuccessTx
+#### SuccessTx (`success-tx`)
 
 - **When**: Transaction confirmed on-chain.
 - **Elements**:
     - "Transaction Confirmed" heading
+    - Decoded action well (shown when the transaction carried recognized
+      calldata; the top-level Amount and To are hidden in that case)
     - Amount + symbol
     - To: color dot + full address + etherscan link
     - Block number
     - Transaction hash: full hash (tap to copy) + etherscan link
     - "Done" button
 - **Transitions**:
-    - "Done" → **AddressToken** (if `selectedToken` set) or **AddressDetail**
+    - "Done" in the approval popup → closes the popup window
+    - "Done" otherwise → resets the navigation stack, then → **AddressToken**
+      (if `selectedToken` set) or **AddressDetail**
 
-#### ErrorTx
+#### ErrorTx (`error-tx`)
 
 - **When**: Transaction broadcast failed, or timed out waiting for confirmation.
 - **Elements**:
@@ -534,24 +619,28 @@ transitions.
       full hash (tap to copy) + etherscan link
     - "Done" button
 - **Transitions**:
-    - "Done" → **AddressToken** (if `selectedToken` set) or **AddressDetail**
+    - "Done" in the approval popup → closes the popup window
+    - "Done" otherwise → resets the navigation stack, then → **AddressToken**
+      (if `selectedToken` set) or **AddressDetail**
 
-#### Receive
+#### Receive (`receive`)
 
-- **When**: User wants to receive funds at this address.
+- **When**: User wants to receive funds at this address, from Home,
+  AddressDetail, or AddressToken.
 - **Elements**:
-    - "Receive" heading, "Back" button
+    - "Back" button, "Receive" heading
     - Instruction text
     - QR code encoding the address
     - Full address (color dot, selectable, etherscan link)
     - "Copy address" button
     - ERC-20 warning (shown when navigating from AddressToken for non-ETH token)
 - **Transitions**:
-    - "Back" → **AddressToken** (if `selectedToken` set) or **AddressDetail**
+    - "Back" → previous screen (Home, AddressDetail, or AddressToken)
 
-#### TransactionDetail
+#### TransactionDetail (`transaction`)
 
-- **When**: User tapped a transaction row from AddressDetail or AddressToken.
+- **When**: User tapped a transaction row on Home, AddressDetail, or
+  AddressToken.
 - **Elements** (grouped into logical blocks using light well containers; field
   labels are self-explanatory so groups have no headings):
     - "Transaction" heading, "Back" button
@@ -576,91 +665,182 @@ transitions.
     - Raw data (shown when calldata is present): full calldata in monospace
       dashed border
 - **Transitions**:
-    - "Back" → **AddressToken** (if `selectedToken` set) or **AddressDetail**
+    - "Back" → previous screen (Home, AddressDetail, or AddressToken)
 
-#### AddToken
+#### AddToken (`add-token`)
 
-- **When**: User wants to track an ERC-20 token on this address.
+- **When**: User wants to track an ERC-20 token, reached from "+ Token" on
+  AddressDetail.
 - **Elements**:
-    - "Add Token" heading, "Back" button
+    - "Back" button, "Add Token" heading
     - Instruction text (find contract address on Etherscan)
     - Contract address input
-    - Token info preview (name, symbol — fetched from contract)
+    - Status line ("Looking up token...", cleared or replaced on failure)
-    - Common token quick-pick buttons
+    - Common token quick-pick buttons (top 25 by market cap), which fill the
+      contract address input
     - "Add" button
 - **Transitions**:
-    - "Add" (valid contract) → **AddressDetail**
+    - "Add" (valid contract) → tracks the token, pops the stack, and re-renders
-    - "Back" → **AddressDetail**
+      **AddressDetail**
+    - "Add" with a token already tracked, a scam-listed address, or a failed
+      contract lookup → flash message, no screen change
+    - "Back" → previous screen (AddressDetail)
 
-#### Settings
+#### Settings (`settings`)
 
-- **When**: User tapped Settings gear from Home.
+- **When**: User tapped the Settings gear.
 - **Elements**:
-    - "Settings" heading, "Back" button
+    - "Back" button, "Settings" heading
-    - Wallets: "+ Add wallet" button
+    - Wallets: one row per wallet with its name (tap to rename inline) and an
-    - Display: "Show tracked tokens with zero balance" checkbox
+      `[x]` delete button, plus a "+ Add wallet" button
-    - Ethereum RPC: endpoint URL input + "Save" button
+    - Tracked Tokens: one row per tracked token with an `[x]` remove button,
-    - Blockscout API: endpoint URL input + "Save" button
+      plus a "+ Add token" button
+    - Display: "Show tracked tokens with zero balance" checkbox and a Theme
+      selector (System / Light / Dark)
+    - Network: network selector (Ethereum Mainnet / Sepolia Testnet); switching
+      resets the RPC and Blockscout endpoints to that network's defaults
+    - Ethereum RPC: endpoint URL input + "Save" button (validated against
+      `eth_chainId` before being saved)
+    - Blockscout API: endpoint URL input + "Save" button (validated against
+      `/stats` before being saved)
     - Token Spam Protection:
         - "Hide tokens with fewer than 1,000 holders" checkbox
         - "Hide transactions from detected fraud contracts" checkbox
         - "Hide dust transactions below N gwei" checkbox + threshold input
+        - "UTC Timestamps" checkbox
     - Allowed Sites: list with remove buttons
     - Denied Sites: list with remove buttons
+    - About: project link, license, author, version, release date, and the
+      commit, which links to the commit in the repository
+    - Debug: hidden until revealed, then an "Enable debug mode" checkbox that
+      turns on the red banner and verbose logging
 - **Transitions**:
     - "+ Add wallet" → **AddWallet**
-    - "Back" (or Settings gear again) → **Home**
+    - "+ Add token" → **SettingsAddToken**
+    - `[x]` on a wallet → **DeleteWallet**
+    - Tap wallet name → inline rename field (no screen change)
+    - `[x]` on a tracked token or a site → removes it in place (no screen
+      change)
+    - Ten clicks on the version → reveals the Debug well (no screen change)
+    - "Back" (or Settings gear again) → previous screen (Home)
 
-#### SiteApproval
+#### DeleteWallet (`delete-wallet-confirm`)
 
-- **When**: A website requests wallet access via `eth_requestAccounts`. Opened
+- **When**: User tapped the `[x]` next to a wallet in Settings.
-  in a separate popup by the background script.
+- **Elements**:
+    - "Back" button, "Delete Wallet" heading
+    - Warning naming the wallet and stating that deletion is permanent and any
+      funds are unrecoverable without the recovery phrase
+    - Error line
+    - Password input
+    - "Confirm Delete" button
+- **Transitions**:
+    - "Confirm Delete" (correct password, other wallets remain) → deletes the
+      wallet and its site permissions, then → **Settings** with a "Wallet
+      deleted." flash message
+    - "Confirm Delete" (correct password, last wallet) → deletes the wallet,
+      clears the selection and the navigation stack, then → **Welcome**
+    - Either way, the active address moves only if it belonged to the deleted
+      wallet, and `AUTISTMASK_ACTIVE_CHANGED` is broadcast when it does
+      (`src/shared/walletDelete.js`)
+    - "Confirm Delete" (wrong password) → "Wrong password." on the error line,
+      nothing deleted
+    - "Back" → previous screen (Settings)
+
+#### SettingsAddToken (`settings-addtoken`)
+
+- **When**: User tapped "+ Add token" in Settings. Tokens added here are tracked
+  across every address, unlike AddToken which is reached from one address.
+- **Elements**:
+    - "Back" button, "Add Token" heading
+    - Instruction text
+    - "Top tokens:" quick-pick buttons (top 10 by market cap; already-tracked
+      tokens are disabled)
+    - "Or pick from top 100:" dropdown (already-tracked tokens are disabled) +
+      "Add selected" button
+    - "Or enter contract address:" input, a status line, and an "Add" button
+- **Transitions**:
+    - Any of the three add paths, on success → adds the token and shows an
+      "Added SYMBOL" flash message (no screen change)
+    - A duplicate, a scam-listed address, or a failed contract lookup → flash
+      message, no screen change
+    - "Back" → previous screen (Settings)
+
+#### SiteApproval (`approve-site`)
+
+- **When**: A website requests wallet access via `eth_requestAccounts` or
+  `wallet_requestPermissions` and is on neither the allowed nor the denied list.
+  The background script prefers the toolbar popup (`action.openPopup()`) and
+  falls back to a separate popup window (`src/background/index.js`,
+  `requestApproval()`).
 - **Elements**:
     - "Connection Request" heading
-    - Site hostname (bold)
+    - Phishing warning banner (shown when the hostname is on the phishing
+      blocklist)
+    - Site hostname (bold) + "wants to connect to your wallet"
     - Address that will be shared (color dot + full address + etherscan link)
     - "Remember my choice for this site" checkbox
     - "Allow" / "Deny" buttons
 - **Transitions**:
-    - "Allow" / "Deny" → closes popup (returns result to background script)
+    - "Allow" / "Deny" → closes popup (returns result to background script; the
+      choice is persisted to the allowed or denied list when "Remember" is
+      checked)
+    - Popup closed without answering → treated as a denial
 
-#### TxApproval
+#### TxApproval (`approve-tx`)
 
 - **When**: A connected website requests a transaction via
-  `eth_sendTransaction`. Opened via the toolbar popup by the background script.
+  `eth_sendTransaction`. Always opened in a separate popup window by the
+  background script (`windows.create()`), because the request is triggered
+  programmatically rather than by a user gesture.
 - **Elements**:
     - "Transaction Request" heading
+    - Phishing warning banner (shown when the hostname is on the phishing
+      blocklist)
     - Site hostname (bold) + "wants to send a transaction"
     - Decoded action (if calldata is recognized): action name, token details,
       amounts, steps, deadline (see Transaction Decoding)
     - From: color dot + full address + etherscan link
-    - To/Contract: color dot + full address + etherscan link (or "contract
+    - Contract: color dot + full address + etherscan link (or "contract
       creation"), token symbol label if known
-    - Value: amount in ETH (4 decimal places)
+    - Value: amount in ETH (4 decimal places, USD in parentheses)
     - Raw data: full calldata displayed inline (shown if present)
-    - Password input
+    - Password input and an error line
     - "Confirm" / "Reject" buttons
 - **Transitions**:
-    - "Confirm" (with password) → closes popup (returns result to background)
+    - "Confirm" (correct password) → decrypts and signs in the popup, hands the
+      signed transaction to the background to broadcast, then → **WaitTx** in
+      the same popup window
+    - "Confirm" (wrong password) → error line, no screen change
     - "Reject" → closes popup (returns rejection to background)
+    - Popup window closed without answering → the request is rejected with
+      EIP-1193 code 4001
 
-#### SignApproval
+#### SignApproval (`approve-sign`)
 
 - **When**: A connected website requests a message signature via
-  `personal_sign`, `eth_sign`, or `eth_signTypedData_v4`. Opened via the toolbar
+  `personal_sign`, `eth_sign`, or `eth_signTypedData_v4`. Opened the same way as
-  popup by the background script.
+  TxApproval, in a separate popup window.
 - **Elements**:
     - "Signature Request" heading
+    - Phishing warning banner (shown when the hostname is on the phishing
+      blocklist)
     - Site hostname (bold) + "wants you to sign a message"
+    - Danger warning box (shown for `eth_sign`, which signs a raw hash)
     - Type: "Personal message" or "Typed data (EIP-712)"
     - From: color dot + full address + etherscan link
     - Message: decoded UTF-8 text (personal_sign) or formatted domain/type/
       message fields (EIP-712 typed data)
-    - Password input
+    - Password input and an error line
     - "Sign" / "Reject" buttons
 - **Transitions**:
-    - "Sign" (with password) → signs locally → closes popup (returns signature)
+    - "Sign" (correct password) → signs locally → closes popup (returns
+      signature)
+    - "Sign" (wrong password, or a signing failure) → error line, no screen
+      change
     - "Reject" → closes popup (returns rejection to background)
+    - Popup window closed without answering → the request is rejected with
+      EIP-1193 code 4001
 
 ### External Services
 
@@ -696,7 +876,7 @@ communicates with three external services to function as a wallet:
 What the extension does NOT do:
 
 - No analytics or telemetry services
-- No token list APIs (user adds tokens manually by contract address)
+- No token list APIs (the top-250 token list is bundled at build time)
 - No Infura/Alchemy dependency (any JSON-RPC endpoint works)
 - No backend servers operated by the developer
 
@@ -815,10 +995,12 @@ hardcoded test phrase.
 - Create new HD wallet (generates 12-word recovery phrase)
 - Import HD wallet from existing 12 or 24 word recovery phrase
 - Import single-address wallet from private key
+- Import multi-address wallet from an extended private key (`xprv`)
 - Add multiple addresses within an HD wallet
 - Manage multiple wallets simultaneously
 - View ETH balance per address
-- View ERC-20 token balances (user adds token by contract address)
+- View ERC-20 token balances (bundled top-250 tokens, tokens with 1,000 or more
+  holders, and tokens the user adds by contract address)
 - Send ETH to an address
 - Send ERC-20 tokens to an address
 - Receive ETH/tokens (display address, copy to clipboard, QR code)
@@ -964,7 +1146,8 @@ Currently supported:
 - Built in token swaps (use a DEX in the browser)
 - Analytics, telemetry, or tracking of any kind
 - Advertisements or promotions
-- Obscure token list auto-discovery (user adds tokens manually)
+- Obscure token list auto-discovery — nothing outside the bundled list, the
+  1,000-holder floor, and the tokens the user added by contract address
     - We detect common/popular ERC20s in the basic case
 - Fiat on/off ramps
 - Extensive transaction decoding/parsing
@@ -986,7 +1169,7 @@ Currently supported:
 
 ### Transactions
 
-- [ ] Gas estimation and fee display before confirming
+- [x] Gas estimation and fee display before confirming
 
 ### Testing
 
@@ -1022,13 +1205,17 @@ covered by the GPL-3.0 license above. These files, their copyright holders, and
 their licenses are:
 
 | File                                                       | Source                                                                                                    | Copyright                         | License                                                        |
-| ---------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | --------------------------------- | -------------------------------------------------------------- |
+| ---------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- | --------------------------------- | -------------------------------------------------------------- |
-| `src/shared/phishingBlocklist.json`                        | [eth-phishing-detect](https://github.com/AugurProject/eth-phishing-detect) community-maintained phishing domain blocklist | Copyright (c) 2018 kumavis        | [DBAD (Don't Be a Dick)](https://github.com/philsturgeon/dbad) |
+| `src/shared/phishingBlocklist.json`                        | `eth-phishing-detect` community-maintained phishing domain blocklist, vendored from its `src/config.json` | Copyright (c) 2018 kumavis        | [DBAD (Don't Be a Dick)](https://github.com/philsturgeon/dbad) |
 | `src/shared/scamlist.js` (address data from MyEtherWallet) | [ethereum-lists](https://github.com/MyEtherWallet/ethereum-lists) `addresses-darklist.json`               | Copyright (c) 2020 MyEtherWallet  | MIT                                                            |
 | `src/shared/scamlist.js` (address data from EtherScamDB)   | [EtherScamDB](https://github.com/MrLuit/EtherScamDB) `scams.yaml`                                         | Copyright (c) 2018 Luit Hollander | MIT                                                            |
 
 The full license texts for these third-party files are included in the
-[LICENSE](LICENSE) file.
+[LICENSE](LICENSE) file. The `eth-phishing-detect` row carries no repository
+link because the upstream is hosted under a competitor's organization name,
+which project policy keeps out of code and documentation; the vendored copy and
+the runtime refresh both come from that upstream, whose URL is the
+`BLOCKLIST_URL` constant in `src/shared/phishingDomains.js`.
 
 ## Author
 

TODO.md

@@ -47,6 +47,12 @@ undefined identifiers, which is how
 - 2026-08-11: Known-answer test coverage for the crypto core — BIP-39/BIP-32
   derivation in `wallet.js` and the Argon2id vault in `vault.js`
   ([#159](https://git.eeqj.de/sneak/AutistMask/issues/159)).
+- 2026-08-11: Three `README.md` claims corrected against the code — blocklist
+  attribution, token-display rule, navigation model
+  ([#213](https://git.eeqj.de/sneak/AutistMask/issues/213)).
+- 2026-08-11: README Screen Map rebuilt from the code — every screen, element
+  and transition re-verified against `src/popup/`
+  ([#164](https://git.eeqj.de/sneak/AutistMask/issues/164)).
 - 2026-08-11: `docs/README.md` rewritten against the code: no competitor names,
   all five network destinations documented, password/Settings/Add Wallet
   sections corrected ([#163](https://git.eeqj.de/sneak/AutistMask/issues/163)).

tests/vault.test.js

@@ -10,9 +10,11 @@
 //
 // Cost: every encrypt and decrypt runs one Argon2id pwhash at the production
 // interactive parameters, which the module hardcodes. The parameters are not
-// weakened or overridden anywhere in this file; the suite is kept inside
+// weakened or overridden anywhere in this file — they are pinned by the "key
-// script/test's 30-second budget by sharing one encrypted fixture across the
+// derivation cost" tests, since they are the vault's only defence against an
-// tamper cases instead of re-encrypting per test.
+// offline attack on a stolen blob. The suite is kept inside script/test's
+// 30-second budget by sharing one encrypted fixture across the tamper cases
+// instead of re-encrypting per test.
 
 const sodium = require("libsodium-wrappers-sumo");
 const {
@@ -155,6 +157,87 @@ describe("fresh salt and nonce", () => {
     });
 });
 
+describe("key derivation cost", () => {
+    // Argon2id's opslimit and memlimit are the whole of the vault's resistance
+    // to an offline attack on a stolen blob, and lowering them breaks nothing
+    // any other test here can see — the suite merely runs faster. So pin them
+    // directly, both to libsodium's INTERACTIVE constants and to the absolute
+    // values those constants must keep meaning.
+    const INTERACTIVE_OPSLIMIT = 2;
+    const INTERACTIVE_MEMLIMIT = 64 * 1024 * 1024;
+
+    test("the interactive constants still mean 2 passes over 64 MiB", () => {
+        expect(sodium.crypto_pwhash_OPSLIMIT_INTERACTIVE).toBe(
+            INTERACTIVE_OPSLIMIT,
+        );
+        expect(sodium.crypto_pwhash_MEMLIMIT_INTERACTIVE).toBe(
+            INTERACTIVE_MEMLIMIT,
+        );
+        // The floor these must never quietly be swapped for: _MIN is one pass
+        // over 8 KiB, an 8192x reduction in memory cost.
+        expect(sodium.crypto_pwhash_OPSLIMIT_MIN).toBeLessThan(
+            INTERACTIVE_OPSLIMIT,
+        );
+        expect(sodium.crypto_pwhash_MEMLIMIT_MIN).toBeLessThan(
+            INTERACTIVE_MEMLIMIT,
+        );
+    });
+
+    test("a key derived at the interactive parameters opens the vault", () => {
+        // Independent of any spy, and of the module's own code path: derive
+        // the key here from the vault's published salt at the interactive cost
+        // and open its ciphertext directly. A vault whose key came from any
+        // other opslimit, memlimit or Argon2id variant yields a different key
+        // and cannot be opened this way.
+        const key = sodium.crypto_pwhash(
+            sodium.crypto_secretbox_KEYBYTES,
+            PASSWORD,
+            b64decode(vault.salt),
+            INTERACTIVE_OPSLIMIT,
+            INTERACTIVE_MEMLIMIT,
+            sodium.crypto_pwhash_ALG_ARGON2ID13,
+        );
+        const opened = sodium.crypto_secretbox_open_easy(
+            b64decode(vault.ciphertext),
+            b64decode(vault.nonce),
+            key,
+        );
+
+        expect(sodium.to_string(opened)).toBe(SECRET);
+    });
+
+    test.each([
+        [
+            "encrypt",
+            async () => {
+                await encryptWithPassword(SECRET, PASSWORD);
+            },
+        ],
+        [
+            "decrypt",
+            async () => {
+                await decryptWithPassword(vault, PASSWORD);
+            },
+        ],
+    ])("%s derives exactly one key at the interactive cost", async (_, run) => {
+        const spy = jest.spyOn(sodium, "crypto_pwhash");
+        try {
+            await run();
+
+            expect(spy).toHaveBeenCalledTimes(1);
+            const [keyBytes, , salt, opslimit, memlimit, alg] =
+                spy.mock.calls[0];
+            expect(keyBytes).toBe(sodium.crypto_secretbox_KEYBYTES);
+            expect(salt).toHaveLength(SALT_BYTES);
+            expect(opslimit).toBe(sodium.crypto_pwhash_OPSLIMIT_INTERACTIVE);
+            expect(memlimit).toBe(sodium.crypto_pwhash_MEMLIMIT_INTERACTIVE);
+            expect(alg).toBe(sodium.crypto_pwhash_ALG_ARGON2ID13);
+        } finally {
+            spy.mockRestore();
+        }
+    });
+});
+
 describe("wrong password", () => {
     test("is rejected, and rejects cleanly", async () => {
         // rejects.toThrow asserts a rejected promise, not a synchronous throw

tests/wallet.test.js

@@ -309,9 +309,8 @@ describe("isValidXprv", () => {
     // and for 9 of those 14 positions the import silently yields a *different*
     // wallet (e.g. 0x3F334f0a356d6B46B1d70B590E7437D77100d28D instead of
     // 0x022b971dFF0C43305e691DEd7a14367AF19D6407) with no error shown.
-    // Reported on the pull request for
+    // Tracked as https://git.eeqj.de/sneak/AutistMask/issues/210; out of scope
-    // https://git.eeqj.de/sneak/AutistMask/issues/159 to be filed as its own
+    // here, which is tests only. Unskip when it is fixed.
-    // issue; out of scope here, which is tests only. Unskip when it is fixed.
     test.skip("rejects an extended key with a one-character typo", () => {
         const index = BIP32_VECTOR_1_XPRV.length - 8;
         const typo =