Rewrite AGENTS.md sentence by sentence

Rewrite the agent rules from scratch, with one idea per sentence and
every file name and command in backticks. Drop the rule that models
embed `models.Base`, which no package has. Say that the linter keeps
tests in external test packages, and that an `export_test.go` file
gives them access to unexported code. Limit the rules on doc comments
and blank imports to files outside the tests. State magic numbers as
a preference, and correct the blank-line rule for `return`. State the
branch workflow: pull requests target `next` and only the owner
merges `next` into `main`. Record the three snake_case JSON tags the
HTTP API keeps.

Part of #190.

Model: fable-5-1 (writing); opus-5-5 (rework)

AGENTS.md

@@ -1,55 +1,73 @@
-# AGENTS.md — Rules for AI Agents
+# Rules for coding agents
 
-## Before Every Commit
+This file holds the rules for coding agents working in this repository.
+`CONVENTIONS.md` defines the architecture. `REPO_POLICIES.md` defines the
+repository standards. Both are copies of shared documents. Do not edit them
+here.
 
-1. **Format**: `make fmt`
-2. **Check**: `make check` — the tests and the linter, which run in Docker, and
-   the format check: all passing, zero issues
+## Before every commit
 
-Never run `go test`, `golangci-lint` or `gofmt` directly; use the `make`
-targets.
+1. Run `make fmt`.
+2. Run `make check`. It runs the tests and the linter in Docker, then the format
+   check. All three must pass with no findings.
 
-No commit lands on main with lint errors, test failures, or formatting issues.
+Never run `go test`, `golangci-lint` or `gofmt` directly. Use the `make` targets
+instead, such as `make test` and `make lint`.
 
-## Code Style
+## Branches and pull requests
 
-- Follow CONVENTIONS.md exactly — it defines the architecture
-- All exported types, functions, methods, and vars must have doc comments
-- All packages must have a package doc comment
-- JSON tags use camelCase (not snake_case)
-- No magic numbers — use named constants
-- No inline error handling (`if err := ...; err != nil`) — use plain assignment
-- Blank line before every `return` statement
-- Blank line separating embedded fields from regular fields in structs
-- Blank imports must have a justification comment
+- Never commit to `main` or `next` directly. Every change is a pull request from
+  a feature branch into `next`.
+- Only the owner merges `next` into `main`.
+- A pull request that closes an issue has the title `Description (closes #N)`.
+- One logical change per commit.
+- Commit messages are in the imperative mood and short.
 
-## Git Workflow
+## Code style
 
-- **Never commit directly to main** — all changes go on feature branches
-- Merge to main only when ready and passing all checks
-- PR titles: `Description (closes #N)` when closing an issue
-- One logical change per commit
-- Commit messages: imperative mood, concise
+- Follow `CONVENTIONS.md`.
+- Outside test files, every package has a package doc comment.
+- Outside test files, every exported type, function and variable has a doc
+  comment.
+- JSON tags are camelCase. The HTTP API's `last_id`, `pow_token` and
+  `hashcash_bits` stay as they are, each with a `//nolint:tagliatelle` comment.
+- Prefer named constants to magic numbers. The `mnd` linter checks for them
+  outside test files.
+- No inline error handling such as `if err := f(); err != nil`. Assign the error
+  on its own line, then test it.
+- A `return` that follows another statement in its block has a blank line before
+  it.
+- A blank line between the embedded fields of a struct and its other fields.
+- Outside test files, every blank import has a comment saying why it is there.
 
 ## Architecture
 
-- Dependency injection via Uber fx — all components are fx providers
-- `internal/` for all application packages — one package per concern
-- Handlers return `http.HandlerFunc` using the closure pattern
-- Request/response structs defined inside handler closures
-- Models embed `models.Base` for database access to relation methods
-- Database migrations in `internal/db/schema/` — embedded via `go:embed`
-- SQLite by default (pure Go driver: modernc.org/sqlite)
+- The server uses `go.uber.org/fx` for dependency injection.
+  `cmd/neoircd/main.go` lists its `fx` providers, such as `db.New` and
+  `handlers.New`.
+- Application packages live under `internal/`, one package per concern.
+- `pkg/irc` holds the IRC command names and numeric reply codes.
+- The `web` package embeds the built web client.
+- Each exported `Handle…` method of `Handlers` returns an `http.HandlerFunc`.
+- A request struct is defined inside the method that decodes it.
+- The server uses the database only through the methods of `db.Database`.
+- The database migrations live in `internal/db/schema/` and are embedded with
+  `go:embed`.
+- The database is SQLite, through the pure Go driver `modernc.org/sqlite`.
 
 ## Testing
 
-- Table-driven tests preferred
-- Use `testing.T` helpers, not assertion libraries
-- Test files live next to the code they test
-- `_test.go` suffix, same package for white-box testing
+- Prefer table-driven tests.
+- Use `testing.T` helpers, not assertion libraries.
+- A test file lives next to the code it tests and ends in `_test.go`.
+- The linter requires each test file to be in the package's external test
+  package, such as `handlers_test`. It allows `export_test.go` and files ending
+  in `_internal_test.go` in the package itself.
+- An `export_test.go` file gives the external tests access to the package's
+  unexported code.
 
 ## Dependencies
 
-- Required libraries are listed in CONVENTIONS.md §1
-- No new dependencies without justification
-- Pure Go preferred (no CGO)
+- The required libraries are listed in `CONVENTIONS.md` §1.
+- No new dependency without a reason given in the pull request.
+- Prefer dependencies written in pure Go, which build without cgo.

schema/README.md

@@ -1,156 +1,98 @@
-# Message schemas
+# Message Schemas
 
-This directory holds JSON Schema files (draft 2020-12) for the messages that the
-neoirc HTTP API carries. `message.json` describes the envelope every message
-uses. `commands/` has files for some of the IRC commands. `numerics/` has files
-for some of the numeric replies. `README.md` at the repository root documents
-the protocol.
+JSON Schema definitions (draft 2020-12) for the neoirc protocol. Messages use
+**IRC command names and numeric reply codes** (RFC 1459/2812) encoded as JSON
+over HTTP.
 
-## The envelope
+## Envelope
 
-Every message is one JSON object. These are the fields it can have:
-
-- `command`: the IRC command name, such as `PRIVMSG`, or the name of a numeric
-  reply, such as `RPL_WELCOME`. Always present.
-- `code`: the number of a numeric reply, such as `1` for `RPL_WELCOME`. Absent
-  on other messages.
-- `id`: the message's UUID, assigned by the server.
-- `from`: the sender's nick, or the server name on a server message.
-- `to`: the target, such as a channel name starting with `#` or a nick.
-- `params`: other parameters, in order, as an array of strings. `KICK` events
-  and many numeric replies have it. The server ignores `params` sent by a
-  client.
-- `body`: an array of strings. It is never a bare string. In a `PRIVMSG` or
-  `NOTICE`, each string is one line of text.
-- `ts`: when the server stored the message, as an RFC 3339 time in UTC, such as
-  `2026-10-27T12:00:00.123Z`.
-- `meta`: an object of extra data, such as a hashcash stamp in `meta.hashcash`.
-  A hashcash stamp is a short string that takes a computer some work to make. A
-  channel with mode `+H` needs one in every `PRIVMSG`. The server relays the
-  `meta` of a `PRIVMSG` or `NOTICE` unchanged. It drops the `meta` of every
-  other command.
-
-A `PRIVMSG` as the IRC listener sends it, and as the HTTP API sends it without
-`id`, `ts` and `meta`:
+Every message is a JSON object with a `command` field. The format maps directly
+to IRC wire format:
 
 ```
-IRC:  :alice!alice@* PRIVMSG #general :hello world
-JSON: {"command": "PRIVMSG", "from": "alice", "to": "#general", "body": ["hello world"]}
+IRC:  :nick PRIVMSG #channel :hello world
+JSON: {"command": "PRIVMSG", "from": "nick", "to": "#channel", "body": ["hello world"]}
+
+IRC:  :server 353 nick = #channel :user1 @op1 +voice1
+JSON: {"command": "353", "to": "nick", "params": ["=", "#channel"], "body": ["user1 @op1 +voice1"]}
+
+Multiline:  {"command": "PRIVMSG", "to": "#ch", "body": ["line 1", "line 2"]}
+Structured: {"command": "PUBKEY", "body": {"alg": "ed25519", "key": "base64..."}}
 ```
 
-A numeric reply has its name in `command` and its number in `code`. This `353`
-reply lists the members of `#general`, again without `id`, `ts` and `meta`:
+Common fields (see `message.json` for full schema):
 
-```
-{"command": "RPL_NAMREPLY", "code": 353, "from": "neoirc", "to": "alice",
- "params": ["=", "#general"], "body": ["@op1!op1@host1 alice!alice@host2"]}
-```
+| Field     | Type            | Description                                          |
+| --------- | --------------- | ---------------------------------------------------- |
+| `id`      | string (uuid)   | Server-assigned message UUID                         |
+| `command` | string          | IRC command or 3-digit numeric code                  |
+| `from`    | string          | Source nick or server name (IRC prefix)              |
+| `to`      | string          | Target: #channel or nick                             |
+| `params`  | string[]        | Middle parameters (mainly for numerics)              |
+| `body`    | array \| object | Structured body — never a raw string (see below)     |
+| `ts`      | string          | ISO 8601 timestamp (server-assigned, not in raw IRC) |
+| `meta`    | object          | Extensible metadata (signatures, hashes, etc.)       |
 
-A `body` with two strings is a two-line message:
+**Structured bodies:** `body` is always an array of strings (for text) or an
+object (for structured data like PUBKEY). Never a raw string. This enables:
 
-```
-{"command": "PRIVMSG", "to": "#general", "body": ["line one", "line two"]}
-```
+- Multiline messages without escape sequences
+- Deterministic canonicalization via RFC 8785 JCS for signing
+- Structured data where needed
 
-## Files
+## Commands
 
-Commands, in `commands/`:
+IRC commands used for client↔server and server↔server communication.
 
-- `PRIVMSG.json`: a message to a channel or a user.
-- `NOTICE.json`: a notice. A client must not answer a notice automatically.
-- `JOIN.json`: a user joined a channel.
-- `PART.json`: a user left a channel.
-- `QUIT.json`: a user left the server.
-- `NICK.json`: a user changed nick.
-- `TOPIC.json`: a channel topic was set.
-- `MODE.json`: a channel mode was changed.
-- `KICK.json`: a channel operator removed a user from a channel.
-- `PING.json`: a check that the server still answers.
-- `PONG.json`: the answer to a `PING`.
-- `PUBKEY.json`: an announcement of a user's public signing key. The server has
-  no such command. It answers a `PUBKEY` with `ERR_UNKNOWNCOMMAND` (421).
+| Command   | File                    | RFC         | Description                |
+| --------- | ----------------------- | ----------- | -------------------------- |
+| `PRIVMSG` | `commands/PRIVMSG.json` | 1459 §4.4.1 | Message to channel or user |
+| `NOTICE`  | `commands/NOTICE.json`  | 1459 §4.4.2 | Notice (no auto-reply)     |
+| `JOIN`    | `commands/JOIN.json`    | 1459 §4.2.1 | Join a channel             |
+| `PART`    | `commands/PART.json`    | 1459 §4.2.2 | Leave a channel            |
+| `QUIT`    | `commands/QUIT.json`    | 1459 §4.1.6 | User disconnected          |
+| `NICK`    | `commands/NICK.json`    | 1459 §4.1.2 | Change nickname            |
+| `TOPIC`   | `commands/TOPIC.json`   | 1459 §4.2.4 | Get/set channel topic      |
+| `MODE`    | `commands/MODE.json`    | 1459 §4.2.3 | Set channel/user modes     |
+| `KICK`    | `commands/KICK.json`    | 1459 §4.2.8 | Kick user from channel     |
+| `PING`    | `commands/PING.json`    | 1459 §4.6.2 | Keepalive                  |
+| `PONG`    | `commands/PONG.json`    | 1459 §4.6.3 | Keepalive response         |
+| `PUBKEY`  | `commands/PUBKEY.json`  | (extension) | Announce/relay signing key |
 
-Numeric replies, in `numerics/`:
+## Numeric Replies
 
-- `001.json`: `RPL_WELCOME`, which welcomes a new user.
-- `002.json`: `RPL_YOURHOST`, the server's name and version.
-- `003.json`: `RPL_CREATED`, the date the server started.
-- `004.json`: `RPL_MYINFO`, the server's version and its lists of modes.
-- `322.json`: `RPL_LIST`, one channel in the answer to `LIST`.
-- `323.json`: `RPL_LISTEND`, the end of the answer to `LIST`.
-- `332.json`: `RPL_TOPIC`, a channel's topic.
-- `353.json`: `RPL_NAMREPLY`, a channel's members.
-- `366.json`: `RPL_ENDOFNAMES`, the end of the member list.
-- `372.json`: `RPL_MOTD`, one line of the message of the day.
-- `375.json`: `RPL_MOTDSTART`, the start of the message of the day.
-- `376.json`: `RPL_ENDOFMOTD`, the end of the message of the day.
-- `401.json`: `ERR_NOSUCHNICK`, the nick does not exist.
-- `403.json`: `ERR_NOSUCHCHANNEL`, the channel does not exist.
-- `433.json`: `ERR_NICKNAMEINUSE`, the nick is taken.
-- `442.json`: `ERR_NOTONCHANNEL`, the user is not on that channel.
-- `482.json`: `ERR_CHANOPRIVSNEEDED`, the user is not a channel operator.
+Three-digit codes for server responses, per IRC convention.
 
-## Where the files differ from the server
+### Success / Informational (0xx–3xx)
 
-Where a schema file and the server disagree, the server is right:
+| Code  | Name           | File                | Description                    |
+| ----- | -------------- | ------------------- | ------------------------------ |
+| `001` | RPL_WELCOME    | `numerics/001.json` | Welcome after session creation |
+| `002` | RPL_YOURHOST   | `numerics/002.json` | Server host info               |
+| `003` | RPL_CREATED    | `numerics/003.json` | Server creation date           |
+| `004` | RPL_MYINFO     | `numerics/004.json` | Server info and modes          |
+| `322` | RPL_LIST       | `numerics/322.json` | Channel list entry             |
+| `323` | RPL_LISTEND    | `numerics/323.json` | End of channel list            |
+| `332` | RPL_TOPIC      | `numerics/332.json` | Channel topic                  |
+| `353` | RPL_NAMREPLY   | `numerics/353.json` | Channel member list            |
+| `366` | RPL_ENDOFNAMES | `numerics/366.json` | End of NAMES list              |
+| `372` | RPL_MOTD       | `numerics/372.json` | MOTD line                      |
+| `375` | RPL_MOTDSTART  | `numerics/375.json` | Start of MOTD                  |
+| `376` | RPL_ENDOFMOTD  | `numerics/376.json` | End of MOTD                    |
 
-- `message.json` and the numeric files put the three-digit code in `command` and
-  have no `code` field. The server puts the reply's name in `command` and its
-  number in `code`.
-- `message.json` allows an object as `body`. The server reads only arrays of
-  strings. A `PRIVMSG` with an object gets `ERR_NOTEXTTOSEND` (412).
-- `message.json` says `to` is a channel or a nick. A `WALLOPS` message has `*`
-  there.
-- `message.json` allows `meta` on every message. The server keeps `meta` only on
-  a `PRIVMSG` or `NOTICE`.
-- `message.json` describes signature fields in `meta`. The server never checks a
-  signature.
-- `message.json` does not describe `meta.hashcash`. The server reads it in a
-  `PRIVMSG` to a channel with mode `+H`.
-- `JOIN.json` has no `body`. A client's `JOIN` can carry the channel key in
-  `body`. When a user joins, the server's `JOIN` event repeats the channel name
-  there.
-- `JOIN.json` allows a channel name of any length. The server allows at most 63
-  characters after the `#`. It answers a longer name with `ERR_NOSUCHCHANNEL`
-  (403).
-- `KICK.json` puts the kicked nick in `params`. The server reads a client's
-  `KICK` from `body`: the nick, then an optional reason.
-- `MODE.json` puts the mode change in `params`. The server uses `body` instead.
-  A client sends the change and any value as separate strings, such as `"+o"`
-  and `"bob"`. The server's `MODE` event has one string such as `"+o bob"`, or
-  the change and its value as two strings, such as `"+k"` and `"secret"`.
-- `NOTICE.json` allows `*` as `to`. The server answers that with
-  `ERR_NOSUCHNICK` (401).
-- `NOTICE.json` has an example notice from the server to `*`. The server sends
-  no such notice.
-- `PING.json` and `PONG.json` describe a token that the `PONG` repeats. The
-  server ignores the `body` of a `PING`. It answers the HTTP request itself with
-  `{"command": "PONG", "from": "<server name>"}`.
-- `PING.json` and `PONG.json` also describe messages between servers. The server
-  does not connect to other IRC servers.
-- `PUBKEY.json` describes a command the server does not have.
-- `QUIT.json` says only the server sends `QUIT`. A client can send it too, to
-  end its session. The client's `QUIT` can carry a reason in `body`.
-- `TOPIC.json` says a `TOPIC` without a `body` queries the topic. Over the HTTP
-  API a `TOPIC` without a `body` gets `ERR_NEEDMOREPARAMS` (461).
-- `TOPIC.json` says an empty array clears the topic. The server answers `[]`
-  with `ERR_NEEDMOREPARAMS` (461). A `body` of `[""]` clears the topic.
-- `003.json` describes the server's creation date. The server sends the date it
-  last started.
-- `004.json` has example mode lists. The server sends an empty string as the
-  user modes and `ikmnostl` as the channel modes.
-- `322.json` says `LIST` gets one reply per channel. The server leaves out each
-  secret channel that the user is not on.
-- `353.json` says `body` lists nicks. Over the HTTP API the server lists
-  `nick!user@host` in place of each nick, such as `@op1!op1@host1`.
-- `353.json` says the first parameter marks a channel as public, private or
-  secret. The server always sends `=`, the mark for a public channel.
-- `376.json` gives the text as `End of /MOTD command`. The server adds a full
-  stop.
-- `401.json` gives the text as `No such nick/channel`. For a `PRIVMSG` or
-  `NOTICE` to an unknown nick, the server sends `No such nick`.
-- `433.json` has an example with `*` as `to`. Over the HTTP API the server sends
-  `433` only in answer to a `NICK`, with the user's nick as `to`.
+### Errors (4xx)
 
-The server also accepts some messages that the files do not allow, such as a
-channel name without its `#`.
+| Code  | Name                 | File                | Description             |
+| ----- | -------------------- | ------------------- | ----------------------- |
+| `401` | ERR_NOSUCHNICK       | `numerics/401.json` | No such nick/channel    |
+| `403` | ERR_NOSUCHCHANNEL    | `numerics/403.json` | No such channel         |
+| `433` | ERR_NICKNAMEINUSE    | `numerics/433.json` | Nickname already in use |
+| `442` | ERR_NOTONCHANNEL     | `numerics/442.json` | Not on that channel     |
+| `482` | ERR_CHANOPRIVSNEEDED | `numerics/482.json` | Not channel operator    |
+
+## Federation (S2S)
+
+Server-to-server messages use the same command format. Federated servers relay
+messages with an additional `origin` field in `meta` to track the source server.
+The PING/PONG commands serve as inter-server keepalives. State sync after link
+establishment uses a burst of JOIN, NICK, TOPIC, and MODE commands.