docs: resync AGENTS.md and the doc comments with the code

AGENTS.md:
- db.rs row claimed a per-store connection pool; there is one shared pool for
  all three tables (statics.rs builds it once).
- retry enqueue moved to send.rs, noted in both handlers rows.
- queue row now names both notifies (workers' + the sweep's).
- Retries bullet documents fetch vs fetch_once.
- test count ~125 -> ~135, the untested-files list no longer claims state.rs
  and handlers.rs are untested, and the live-test inventory mentions the
  token-gated, not-#[ignore]d pixiv download test that makes a local
  `cargo test --workspace` hit the network.
- /bot_dict is admin-only now.

Code docs:
- site/mod.rs: the module doc pointed new sites at `fetch_once` (a name that
  did not exist then and now means a single-attempt fetch) -> `SITES`; the
  cache_key/SITES/Site docs still said "twitter -> bsky -> pixiv" (misskey
  is registered third); RenderData now documents which fields are escaped
  and why url/author_url are not.
- state.rs, callback.rs: drop the pre-misskey site list and the `<name>`
  that rustdoc read as an HTML tag.
- Fixed the remaining rustdoc links/warnings: `cargo doc --workspace
  --no-deps` is now warning-free (was 8).
- docs/site-registry-refactor.md: §1 describes the pre-refactor state; said so.

No behavior change. fmt/clippy clean, 55 + 68 tests pass (the live pixiv
download test flaked on a CDN body timeout, as before).

AGENTS.md

@@ -32,11 +32,11 @@ The `x-media` library: `site::fetch(url)` dispatches through the `SITES` registr
 | `crates/x-media/src/site/<twitter\|pixiv\|bsky\|misskey>/` | One directory per site: `mod.rs` (re-exports), `interface.rs` (PATTERN, `enabled()`, `fetch_from_url()`, `cache_key`/`is_retryable`/`media_headers`, unit struct `<Name>Site` implementing `site::Site`, `From<SiteStruct> for Fetched`), `model.rs` (serde DTOs). Pixiv adds `api.rs` (auth + transport); twitter adds `auth.rs` (logged-in GraphQL `TweetDetail` fallback for NSFW tweets, gated on `TWITTER_AUTH_TOKEN`). Misskey targets misskey.io only (`POST /api/notes/show`, 400+`NO_SUCH_NOTE` → NotFound). Twitter's `from_syndication_json` HTML-decodes the API text — syndication and GraphQL `full_text` both arrive pre-escaped (`&gt;` `&lt;` `&amp;` `&#39;`) — so the stored text is raw and the caption escapes exactly once |
 | `crates/xmedia-bot/src/main.rs` | Entry point: env/log init, command registration (`register_commands`), shared `send::BOT` force-init, queue worker start, site login validation (`site::validate_all`), 300 s edit-expiry sweep, dptree handler tree, webhook vs polling dispatch |
 | `crates/xmedia-bot/src/config.rs` | Manual env parsing into `Config` |
-| `crates/xmedia-bot/src/db.rs` | `DbPool`: per-store SQLite connection pool (`POOL_SIZE = 4`, WAL, busy_timeout) over `$DATA_DIR/task_queue.db` (default `data/`); `open_store` creates file + schema, `with_conn` runs all rusqlite I/O in `spawn_blocking` |
-| `crates/xmedia-bot/src/handlers/` | Handler modules: `mod.rs` (message entry point, `reply`, `log_key`), `commands.rs` (teloxide `BotCommands` enum + command executor, incl. the `/test <url>` parse-only debug command), `urls.rs` (URL extraction + bounded job channel (256) drained by `URL_WORKERS = 8` workers (`start_url_workers`) — backpressure instead of unbounded spawns; teloxide's per-chat workers are sequential — batch-forwards need concurrency), `inline.rs`/`callback.rs` (inline queries / edit-before-forward buttons), `statics.rs` (global statics) |
+| `crates/xmedia-bot/src/db.rs` | `DbPool`: one shared SQLite connection pool (`POOL_SIZE = 4`, WAL, busy_timeout) for all three tables over `$DATA_DIR/task_queue.db` (default `data/`) — the three stores share it; `open_store` creates file + schema, `with_conn` runs all rusqlite I/O in `spawn_blocking` |
+| `crates/xmedia-bot/src/handlers/` | Handler modules: `mod.rs` (message entry point, `reply`, `log_key`), `commands.rs` (teloxide `BotCommands` enum + command executor, incl. the `/test <url>` parse-only debug command and the admin-only `/bot_dict` state dump), `urls.rs` (URL extraction + bounded job channel (256) drained by `URL_WORKERS = 8` workers (`start_url_workers`) — backpressure instead of unbounded spawns; teloxide's per-chat workers are sequential — batch-forwards need concurrency), `inline.rs`/`callback.rs` (inline queries / edit-before-forward buttons), `statics.rs` (global statics) |
 | `crates/xmedia-bot/src/state.rs` | `ChatStore`: parking_lot `Mutex<HashMap>` cache + SQLite write-through (`chat_state` table) |
 | `crates/xmedia-bot/src/link_cache.rs` | `LinkCache`: SQLite-backed cache (`link_cache` table) of successfully sent posts — raw caption fields + Telegram `file_id`s; repeat links re-send locally (no fetch/upload), TTL + prune, invalidated on permanent send failure |
-| `crates/xmedia-bot/src/queue.rs` | `PersistentTaskQueue`: SQLite-backed queue (`tasks` table), `QUEUE_WORKERS = 4` concurrent workers (lease via `BEGIN IMMEDIATE` + `locked_until` TTL), retry→dead-letter, `Notify::notify_waiters` wakeup, `busy_timeout` on all connections |
+| `crates/xmedia-bot/src/queue.rs` | `PersistentTaskQueue`: SQLite-backed queue (`tasks` table), `QUEUE_WORKERS = 4` concurrent workers (lease via `BEGIN IMMEDIATE` + `locked_until` TTL), retry→dead-letter, `notify_one` worker wakeup plus a separate `Notify` for the 30 s lease-expiry sweep (a shared one let the sweep steal the workers' wakeup permit), `busy_timeout` on all connections |
 | `crates/xmedia-bot/src/send.rs` | Media senders, upload fallback, error classification, queue task handlers |
 | `crates/xmedia-bot/src/media_sender.rs` | `MediaSender` trait: the send surface (`send_media_group`/`send_animation`/`copy_messages`/`send_message`/`send_chat_action`) implemented by teloxide `Bot` (per-chat rate-limited) and by a scripted `MockSender` in tests |
 | `crates/xmedia-bot/src/rate_limit.rs` | Per-chat token bucket (`CAPACITY = 20`, ~20 msg/min refill) paced before sends reach the API so batch forwards don't trip flood control |
@@ -64,7 +64,7 @@ Docker: `docker build -t tgxmb .` then `docker run --rm -d --name tgxmb --env-fi
 - **Site adapter convention**: each site module exports `PATTERN: LazyLock<Regex>`, `enabled() -> bool`, `fetch_from_url(url) -> Result<Fetched, FetchError>`, plus `cache_key`/`is_retryable`/`media_headers`, and a unit struct `<Name>Site` implementing `site::Site`; the central dispatcher (`site/mod.rs`) only iterates the `SITES` registry. Adding a site = new `site/<name>/{mod.rs,interface.rs,model.rs}` + one `Box::new(...)` entry in `SITES` — the bot crate never lists sites (SetFormat whitelist, cache-key site lookup and startup validation all derive from the registry). Async trait methods return `SiteFuture` (a boxed `Pin<Box<dyn Future + Send>>`) because `async fn` in traits is not dyn-compatible.
 - **Serde**: per-site `model.rs` are pure `Deserialize` DTOs mirroring API JSON; site structs in `interface.rs` have private fields, a `caption()` builder, and `impl From<SiteStruct> for Fetched`. Persisted payloads use internally-tagged enums (`#[serde(tag = "kind")]` / `type`).
 - **Naming**: module-per-concern, snake_case files, `CamelCase` types, `snake_case` fns. `//!` module docs and `///` docs on non-obvious logic (syndication token, ugoira encoding, `display_text_range`).
-- **Retries**: only `x-media::site::fetch` retries (3 attempts, `1 << attempt` backoff, HTTP errors only). Queue retries are explicit `QueueError::Retryable` with computed delay (`retry_delay_seconds`).
+- **Retries**: only `x-media::site::fetch` retries (3 attempts, `1 << attempt` backoff, HTTP errors only); `site::fetch_once` is the same code path with a single attempt, used by inline queries whose answer window is shorter than the backoff. Queue retries are explicit `QueueError::Retryable` with computed delay (`retry_delay_seconds`).
 - Logging via `log` macros (`pretty_env_logger`, level from `RUST_LOG`). Level convention: `info` = lifecycle + per-post business results (`sent`/`forwarded`/`copied`), admin/operator actions and anomalies (fallback, retry enqueue, dead-letter is `error`); `debug` = per-request detail (message/command/URL extraction, `fetching`/`fetched`, batch sends, queue processing, photo processing, inline queries). Full user-submitted URLs and message text only appear at `debug`; at `info` and above links are printed via the normalized cache key (`handlers::log_key`, e.g. `[key=twitter:123...]`) so logs stay short and do not echo user data.
 
 ## Important Files
@@ -72,7 +72,7 @@ Docker: `docker build -t tgxmb .` then `docker run --rm -d --name tgxmb --env-fi
 | File | Why it matters |
 |---|---|
 | `crates/xmedia-bot/src/main.rs` | Startup sequence, webhook vs polling, graceful shutdown (SIGINT via teloxide ctrlc / SIGTERM via `stop_token` for docker, → sweep stop → admin msg → queue stop) |
-| `crates/xmedia-bot/src/handlers/` | `statics.rs` = `CHAT_STORE`/`TASK_QUEUE`/`CONFIG` singletons (open `$DATA_DIR/task_queue.db`, default `data/` **relative to CWD**, dir auto-created); `commands.rs` = command dispatch (incl. the `/test <url>` parse-only debug command); `urls.rs` = URL extraction + retry enqueue; `inline.rs`/`callback.rs` = inline queries / edit-before-forward buttons |
+| `crates/xmedia-bot/src/handlers/` | `statics.rs` = `CHAT_STORE`/`TASK_QUEUE`/`CONFIG` singletons (open `$DATA_DIR/task_queue.db`, default `data/` **relative to CWD**, dir auto-created); `commands.rs` = command dispatch (incl. the `/test <url>` parse-only debug command and the admin-only `/bot_dict` state dump); `urls.rs` = URL extraction + the per-URL pipeline (`enqueue_retry` lives in `send.rs`); `inline.rs`/`callback.rs` = inline queries / edit-before-forward buttons |
 | `crates/xmedia-bot/src/send.rs` | Constants `MAX_MEDIA_GROUP = 9`; fallback chain; `classify_request_error`; download-and-reupload fallback triggered only by Telegram API errors (`is_media_fetch_failure` / `is_size_error`) |
 | `crates/xmedia-bot/src/photo.rs` | Pure-Rust photo processing (no ffmpeg): `png` (image-png) decode/encode + `zune-jpeg` decode + `fast_image_resize` Lanczos3 downscale + `jpeg-encoder`. Photos over Telegram's limits (width + height > 10000 px → `PHOTO_INVALID_DIMENSIONS`; bytes > 10 MiB) are decoded, downscaled keeping the format, PNG bit depth > 24 (RGBA 32-bit / 16-bit per channel) reduced to 24-bit RGB with alpha flattened white (≤24-bit untouched, never upconverted), and transcoded to JPEG only if still over the cap; memory budget guarded, otherwise the item's smaller fallback URL |
 | `crates/x-media/src/site/mod.rs` | Dispatcher, `Fetched`/`FetchError`, shared `CLIENT`, `download_media` (adds `Referer: https://www.pixiv.net/` for `pximg.net` hotlink protection) |
@@ -96,10 +96,10 @@ Docker: `docker build -t tgxmb .` then `docker run --rm -d --name tgxmb --env-fi
 
 ## Testing & QA
 
-- **~125 tests, all inline `#[cfg(test)] mod tests`** — no `tests/` integration directories. Framework: built-in Rust test + `#[tokio::test]` (dev-deps only in `x-media`: tokio macros/rt-multi-thread, dotenv).
+- **~135 tests, all inline `#[cfg(test)] mod tests`** — no `tests/` integration directories. Framework: built-in Rust test + `#[tokio::test]` (dev-deps only in `x-media`: tokio macros/rt-multi-thread, dotenv).
 - No mocking framework anywhere (no mockito/wiremock/mockall). Conventions: pure-function units (regex parsing, serde round-trips, chunking, retry math) tested synchronously; async tests use real dependencies — file-backed SQLite via `tempfile` (`queue.rs::new_queue()` helper), live network fetches.
-- Live-network tests exist in `site/twitter/interface.rs` (5), `site/bsky/interface.rs` (2), `site/misskey/interface.rs` (1), `site/pixiv/api.rs` (1); `photo.rs` adds one `#[ignore = "heavy: …"]` test. Test gating convention (enforced by `.github/workflows/ci.yml`): pure unit tests always run; live-network tests carry `#[ignore = "live network: ..."]` (run via `cargo test --workspace -- --ignored live`); token-gated pixiv tests early-return when `PIXIV_REFRESH_TOKEN` is absent **or empty** (an unset GitHub secret arrives as `""` — `is_err()` alone would run them tokenless and fail). Run the full offline suite with `cargo test --workspace`.
+- Live-network tests exist in `site/twitter/interface.rs` (5), `site/bsky/interface.rs` (2), `site/misskey/interface.rs` (1), `site/pixiv/api.rs` (1); `photo.rs` adds one `#[ignore = "heavy: …"]` test. `site/mod.rs` also has a **token-gated but not `#[ignore]`d** pixiv download test (`download_media_pixiv_original_with_referer`): it hits `i.pximg.net` whenever `PIXIV_REFRESH_TOKEN` is set, so a local `cargo test --workspace` is not fully offline and can flake on a pixiv CDN body timeout. Test gating convention (enforced by `.github/workflows/ci.yml`): pure unit tests always run; live-network tests carry `#[ignore = "live network: ..."]` (run via `cargo test --workspace -- --ignored live`); token-gated pixiv tests early-return when `PIXIV_REFRESH_TOKEN` is absent **or empty** (an unset GitHub secret arrives as `""` — `is_err()` alone would run them tokenless and fail). Run the full offline suite with `cargo test --workspace`.
 - Fixtures are inline `serde_json::json!` builder fns (`fixture()`, `thread_json()`, `illust_json()`), not files. The shared `CLIENT` sets `pool_max_idle_per_host(0)` under `#[cfg(test)]` to avoid cross-runtime `DispatchGone`.
 - **CI** — `.github/workflows/ci.yml` runs `cargo fmt --check` + `cargo clippy --workspace --all-targets -- -D warnings` + `cargo test --workspace` + a `actions-rust-lang/audit` dependency-vulnerability gate (offline, no secrets, on every push/PR) and a `live` job (schedule/manual/tag only, `PIXIV_REFRESH_TOKEN`/`TWITTER_AUTH_TOKEN` from secrets, `continue-on-error`) for the `#[ignore]`d live + token tests. `.github/workflows/docker.yml` builds/pushes the image only.
-- Untested and hard to test without a mock seam: `handlers.rs` (depends directly on teloxide `Bot`); `main.rs`, `config.rs`, `state.rs`; `media.rs`, `lib.rs`, all `model.rs`.
+- Untested and hard to test without a mock seam: `main.rs`, `config.rs`, `db.rs`, `media_sender.rs` (holds `MockSender` itself); `handlers/mod.rs`, `handlers/callback.rs`, `handlers/statics.rs` (need a real teloxide `Bot`); `media.rs`, `lib.rs`, all `model.rs`. `handlers/urls.rs`/`handlers/commands.rs`/`send.rs`/`state.rs`/`queue.rs`/`link_cache.rs`/`rate_limit.rs` are covered through their injected stores and the scripted `MockSender`.
 - No coverage tracking.

crates/x-media/src/site/mod.rs

@@ -2,7 +2,7 @@
 //!
 //! Dispatch order: twitter → bsky → misskey → pixiv. Each site module
 //! exports a `PATTERN`, `enabled()` and `fetch_from_url()`; a future site
-//! plugs in by adding one guarded entry in [`fetch_once`].
+//! plugs in by adding one guarded entry in `SITES`.
 
 use std::future::Future;
 use std::pin::Pin;
@@ -24,9 +24,9 @@ pub use pixiv::PixivError;
 /// media list and spoiler flag. Produced by [`fetch`].
 #[derive(Debug)]
 pub struct Fetched {
-    /// Canonical URL: x.com/{author}/status/{id} |
-    /// https://www.pixiv.net/artworks/{id} |
-    /// https://bsky.app/profile/{handle}/post/{rkey}
+    /// Canonical URL: `x.com/{author}/status/{id}` |
+    /// `https://www.pixiv.net/artworks/{id}` |
+    /// `https://bsky.app/profile/{handle}/post/{rkey}`
     pub source_url: String,
     /// The exact HTML produced by the site's caption().
     pub caption: String,
@@ -46,8 +46,15 @@ pub struct Fetched {
     pub(crate) _keep_alive: Option<tempfile::TempDir>,
 }
 
-/// Pre-escaped values for `{url} {author} {author_url} {title} {tags}`
-/// placeholders in user-supplied caption formats.
+/// Values for the `{url} {author} {author_url} {title} {tags}` placeholders in
+/// user-supplied caption formats, substituted by [`caption_from_fields`] as
+/// HTML text (never as an attribute value).
+///
+/// `author`, `title` and `tags` come from the site API (post text, display
+/// names) and are HTML-escaped at construction. `url` and `author_url` stay
+/// raw: they are canonical URLs the adapter builds from numeric ids and
+/// API-constrained handles/DIDs, so they carry no escapable character — the
+/// bot's `/test` report relies on that when it embeds them.
 #[derive(Debug)]
 pub(crate) struct RenderData {
     pub url: String,
@@ -166,7 +173,7 @@ pub fn caption_from_fields(
 /// Stable per-post cache key derived from any supported URL, so variant
 /// domains (x.com / twitter.com / fxtwitter.com, mobile, `/photo/N`
 /// suffixes) map to the same post. Delegates to each registered site's
-/// `cache_key` (dispatch order twitter → bsky → pixiv).
+/// `cache_key` (in registry order).
 pub fn cache_key(url: &str) -> Option<String> {
     SITES.iter().find_map(|site| site.cache_key(url))
 }
@@ -275,20 +282,21 @@ pub(crate) fn log_once_ffmpeg_missing() {
     }
 }
 
-/// Site adapter: one impl per supported site (twitter / bsky / pixiv),
-/// registered in [`SITES`]. All site-specific knowledge — URL pattern,
+/// Site adapter: one impl per supported site (twitter / bsky / misskey /
+/// pixiv), registered in `SITES`. All site-specific knowledge — URL pattern,
 /// cache-key format, fetch, retry policy, media-host headers, startup
 /// validation — lives in the site module; the central dispatcher only
 /// iterates the registry.
 ///
-/// Async methods return a boxed future (see [`SiteFuture`]): `async fn` /
+/// Async methods return a boxed future (see `SiteFuture`): `async fn` /
 /// RPITIT in traits are not dyn-compatible (verified on rustc 1.95), and
 /// `+ Send` is required since URL/queue workers spawn these futures. The
 /// site structs are stateless unit structs, so the boxed futures never
 /// borrow from `self` beyond the call's scope.
 pub trait Site: Send + Sync {
-    /// Stable site id (`"twitter"` / `"bsky"` / `"pixiv"`): caption-format
-    /// lookup, cache-key prefixes and the SetFormat whitelist derive from it.
+    /// Stable site id (`"twitter"` / `"bsky"` / `"misskey"` / `"pixiv"`):
+    /// caption-format lookup, cache-key prefixes and the SetFormat whitelist
+    /// derive from it.
     fn id(&self) -> &'static str;
     /// URL pattern; the dispatcher's first match wins (dispatch order).
     fn pattern(&self) -> &'static Regex;
@@ -324,8 +332,8 @@ pub trait Site: Send + Sync {
 type SiteFuture<'a, T, E = FetchError> = Pin<Box<dyn Future<Output = Result<T, E>> + Send + 'a>>;
 
 /// The one registry of supported sites, in dispatch order (twitter → bsky →
-/// pixiv). Adding a site = new module + one `Box::new(...)` entry here; the
-/// bot crate never lists sites itself.
+/// misskey → pixiv). Adding a site = new module + one `Box::new(...)` entry
+/// here; the bot crate never lists sites itself.
 static SITES: LazyLock<Vec<Box<dyn Site>>> = LazyLock::new(|| {
     vec![
         Box::new(twitter::TwitterSite),

crates/xmedia-bot/src/handlers/callback.rs

@@ -1,5 +1,5 @@
-//! Callback query handling: the edit-before-forward prompt's "forward" and
-//! "template|<name>" buttons.
+//! Callback query handling: the edit-before-forward prompt's `"forward"` and
+//! `"template|<name>"` buttons.
 
 use super::{CHAT_STORE, CONFIG, TASK_QUEUE};
 use crate::db::unix_now;

crates/xmedia-bot/src/link_cache.rs

@@ -5,7 +5,7 @@
 //! key]. A repeated link is then answered entirely from local state — no
 //! re-fetch of the source site, no re-upload — and no media file is stored
 //! on disk (the file ids point at Telegram's servers). Entries expire after
-//! [`Config::link_cache_ttl`]; a stale entry is dropped lazily on read and
+//! `Config::link_cache_ttl`; a stale entry is dropped lazily on read and
 //! by the periodic prune in `main`.
 
 use crate::db::now_f64;

crates/xmedia-bot/src/send.rs

@@ -271,10 +271,11 @@ pub async fn invalidate_cache_with(cache: &LinkCache, task: &Task) {
 
 /// Locally produced media files (ugoira MP4, bsky remux MP4) whose temp dirs
 /// must stay alive while their task may be retried by the queue. The fetch
-/// pipeline hands ownership here via [`x_media::site::Fetched::take_keep_alive`]
-/// before the [`Fetched`] is dropped; a queued retry runs after that drop, so
-/// without this the local file would be gone by the time the retry sends it.
-/// Entries are removed when the task settles (see [`release_keep_alive`]).
+/// pipeline hands ownership here via
+/// [`x_media::site::Fetched::take_keep_alive`] before that
+/// [`x_media::site::Fetched`] is dropped; a queued retry runs after that drop,
+/// so without this the local file would be gone by the time the retry sends
+/// it. Entries are removed when the task settles (see [`release_keep_alive`]).
 pub static KEEP_ALIVE: LazyLock<parking_lot::Mutex<Vec<tempfile::TempDir>>> =
     LazyLock::new(|| parking_lot::Mutex::new(Vec::new()));
 

crates/xmedia-bot/src/state.rs

@@ -17,8 +17,8 @@ pub struct ChatData {
     pub edit_message: HashMap<i64, EditMessage>,
     /// name -> HTML template containing "[]"
     pub template: HashMap<String, String>,
-    /// site name (twitter/bsky/pixiv) -> user-supplied caption format with
-    /// {url} {author} {author_url} {title} {tags} placeholders.
+    /// site name (twitter/bsky/misskey/pixiv) -> user-supplied caption format
+    /// with {url} {author} {author_url} {title} {tags} placeholders.
     pub message_format: HashMap<String, String>,
 }
 

docs/site-registry-refactor.md

@@ -10,6 +10,10 @@
 
 ## 1. 现状摩擦清单
 
+> ⚠️ 本节记录的是**重构前**的现状：其中的行号、以及 `site/mod.rs` 里的
+> `fetch_once` 分派函数（当时的实现）都已不存在，仅作历史记录。当前形态见
+> `site/mod.rs` 的 `SITES` 注册表——新增站点 = 新模块 + 注册一行。
+
 以现有三站（twitter / bsky / pixiv）为基线，新增第 4 个站点（代号 `example`）
 今天需要触碰的位置：