fix: say a contract creation has no recipient instead of a blank line (closes #250)

A transaction with no `to` showed a blank address, with a colour dot whose
colour was `undefined`, on the wait, success and error screens, the
transaction detail view and the history rows on Home, AddressDetail and
AddressToken. The approval screen showed "(contract creation)".

All of them now say "This transaction creates a new contract. It has no
recipient." The three history lists draw a row's counterparty lines through
one helper in helpers.js. A transaction with a real `to` is unchanged. The
new test drives each screen and list both ways.

Model: opus-5-5

README.md

@@ -1258,7 +1258,10 @@ view would leave a wallet one click from deletion.
       of every wallet, deduplicated by hash and filtered. Each row is three
       lines: age and direction, then the counterparty's colour dot (with our own
       name for it, where it is one of our addresses) and the amount, then the
-      counterparty's full address on a row of its own
+      counterparty's full address on a row of its own. A contract creation has
+      no counterparty: its second line is the amount alone and its third line
+      says "This transaction creates a new contract. It has no recipient." The
+      transaction lists on AddressDetail and AddressToken draw the same rows
     - "Add additional wallet..." link at bottom
 - **Transitions**:
     - Tap address row → sets the active address and broadcasts
@@ -1451,7 +1454,9 @@ view would leave a wallet one click from deletion.
 - **Elements**:
     - "Transaction Broadcast" heading (no back button — tx is irreversible)
     - Amount + symbol
-    - To: color dot + full address + etherscan link
+    - To: color dot + full address + etherscan link; for a contract creation,
+      which has no recipient, "This transaction creates a new contract. It has
+      no recipient." instead
     - Transaction hash: full hash (tap to copy) + etherscan link
     - Count-up timer: "Waiting for confirmation... Ns"
 - **Behavior**: Polls `getTransactionReceipt` every 10 seconds. The wait is
@@ -1480,7 +1485,8 @@ view would leave a wallet one click from deletion.
     - 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
+    - To: color dot + full address + etherscan link, or for a contract creation
+      the same sentence as on WaitTx
     - Block number
     - Transaction hash: full hash (tap to copy) + etherscan link
     - "Done" button
@@ -1495,7 +1501,8 @@ view would leave a wallet one click from deletion.
 - **Elements**:
     - "Transaction Failed" heading
     - Amount + symbol
-    - To: color dot + full address + etherscan link
+    - To: color dot + full address + etherscan link, or for a contract creation
+      the same sentence as on WaitTx
     - Error message (dashed border box)
     - Transaction hash section (hidden if broadcast failed before getting hash):
       full hash (tap to copy) + etherscan link
@@ -1533,7 +1540,7 @@ view would leave a wallet one click from deletion.
     - From: blockie + color dot + full address (tap to copy) + etherscan link;
       ENS name if available
     - To: blockie + color dot + full address (tap to copy) + etherscan link; ENS
-      name if available
+      name if available. For a contract creation, the same sentence as on WaitTx
     - Time: ISO datetime + relative age in parentheses
     - Block: block number (tap to copy) + etherscan block link
     - Amount: value + symbol (bold)
@@ -1844,8 +1851,8 @@ view would leave a wallet one click from deletion.
     - Decoded action (if calldata is recognized): action name, token details,
       amounts, steps, deadline (see Transaction Decoding)
     - From: color dot + full address + etherscan link
-    - Contract: color dot + full address + etherscan link (or "contract
-      creation"), token symbol label if known
+    - Contract: color dot + full address + etherscan link, token symbol label if
+      known; for a contract creation, the same sentence as on WaitTx
     - Value: amount in ETH (4 decimal places, USD in parentheses)
     - Network fee (max): gas limit × fee per gas in ETH (4 decimal places, USD
       in parentheses), with the gas limit and the fee per gas in gwei below it