test: drop redundant tests, make the vacuous ones real

Audit of all 205 tests (five read-only passes plus a line-by-line
re-check). Ten test functions were removed or merged and eight
subsumed assertion blocks trimmed; the suite is down to 180 tests with
no loss of mutation coverage, and four tests that were passing for
nothing now fail when the code they name is broken.

Redundant (deleted or merged):
- twitter: `syndication_text_only_has_no_media` (re-asserts its own
  empty fixture), `..._keeps_multibyte_text` (both transforms are
  no-ops for that text), `..._strips_trailing_short_link_without_entities`
  (same branch as `..._media_short_link`, which now also covers the
  real multibyte tweet), `..._regardless_of_index_units` (its
  `display_text_range` rationale outlived the function it described).
- pixiv: `test_fetch` (a bare `is_ok()` on the illustration
  `download_media_pixiv_original_with_referer` already asserts and
  downloads, and the only network touch in a plain `cargo test`),
  `startup_validation_only_disables_on_a_definitive_failure` (four rows
  that are a subset of the retry-policy table; the `validate()` branch
  it was named for is not asserted at all).
- bilibili: `from_item_legacy_draw_shape_still_parses` (its fixture is
  the same legacy `draw` shape `from_item_maps_draw_images_and_topic`
  builds, with a subset of its assertions).
- site/mod.rs: two `Ok(None)` cases merged into one test.
- urls.rs: `cache_hit_success_keeps_the_cache_entry` (the `/test` test
  asserts the same two things under stricter settings), plus a
  `assert_ne!` loop that re-states the mapping assertions above it.
- send/mod.rs: `media_group_success_and_forward_ok` (the forward half is
  covered by `post_send_forwards_immediately_when_configured`; the
  `is_ok()` half cannot see the returned file ids), and two boundary
  rows implied by the constant they sit next to.
- commands.rs: the parse tail that `every_documented_invocation_parses`
  already covers per README form, and three `debug_report` rows the
  escaping test pins with stronger input.

Passing for nothing (now real):
- `truncate_caption_does_not_split_an_html_entity` — the cut lands
  inside the entity, so `!contains("&amp")` never fired; it now asserts
  the exact output in both directions and fails when the guard in
  `truncate_caption` is deleted (verified).
- `pipeline_resizes_oversized_jpeg` — magic bytes and a non-empty buffer
  pass for a copy-through; it now decodes the output's headers and
  fails when the JPEG branch skips the resize (verified).
- `live_validate_with_bogus_token_fails` — expected `PixivError::Api`,
  which the status check before the body read made unreachable; a bogus
  token is a 4xx. Confirmed against the live endpoint: the old
  assertion fails with `got Err(Status(400))`, the new one passes.
- bsky `live_fetch_with_photos` — its URL is a text-only post and it had
  a byte-identical twin, so no live test pinned media; it now points at a
  labelled post with photos and asserts media + the label (live-verified).

Also fixed, found by turning the runtime-sweep test into a real one:
the 30 s lease-expiry sweep recovered crashed rows but never woke a
worker, so a recovered task waited for the next unrelated enqueue (every
worker is parked on `notify` when no row is pending). `recover_update`
now reports its count, `recover_expired` wakes a worker when it changed
something, and `runtime_sweep_recovers_expired_lease` drives the spawned
loop with a paused clock instead of calling the recovery by hand — it
fails on both the missing wake-up and a sweep that recovers nothing.

Verified: `cargo fmt --check`, `cargo clippy --workspace --all-targets
--locked -- -D warnings`, `cargo test --workspace --locked` (180 passed,
14 ignored) and `cargo test -p x-media -- --ignored live` (13 passed).

AGENTS.md

@@ -44,7 +44,7 @@ The `x-media` library: `site::fetch(url)` dispatches through the `SITES` registr
 | `crates/xmedia-bot/src/handlers/` | Handler modules: `mod.rs` (message entry point, `reply`, `log_key`, the group-only `GROUP_LINK_HINT` for a supported link posted outside a private chat), `commands.rs` (teloxide `BotCommands` enum + command executor, incl. `/test <url>` (send-only) / `/debug <url>` (parse-only) and the admin-only `/bot_dict` state dump; `/set_format` rejects unknown `{…}` placeholders and resets with `-`), `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, incl. `skip`; a forward that fails retryably is both queued *and* settles the prompt — the queued row carries the message ids itself, and a prompt left live let a second Confirm copy the same messages twice and let Skip answer "nothing was forwarded" while the row still delivered), `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, a `lease_token` fence: `lease_next` stamps a random token and every write-back (heartbeat, `delete`, `reschedule`, `mark_done`) is guarded by it, so a lease that expired and was re-leased cannot be written by its former holder — a lost lease stops the attempt instead; a finished row's `DELETE`/reschedule retried and a failed delete falling back to a `done` tombstone (the lease query and the sweep only look at `pending`/`in_progress`, so a task that already ran cannot be resurrected and re-run), `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/queue.rs` | `PersistentTaskQueue`: SQLite-backed queue (`tasks` table), `QUEUE_WORKERS = 4` concurrent workers (lease via `BEGIN IMMEDIATE` + `locked_until` TTL), retry→dead-letter, a `lease_token` fence: `lease_next` stamps a random token and every write-back (heartbeat, `delete`, `reschedule`, `mark_done`) is guarded by it, so a lease that expired and was re-leased cannot be written by its former holder — a lost lease stops the attempt instead; a finished row's `DELETE`/reschedule retried and a failed delete falling back to a `done` tombstone (the lease query and the sweep only look at `pending`/`in_progress`, so a task that already ran cannot be resurrected and re-run), `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; the sweep does notify the workers after it actually recovered a row, since a recovered task is due immediately while every worker may be parked on `notify` with no pending row to sleep on), `busy_timeout` on all connections |
 | `crates/xmedia-bot/src/ctx.rs` | `AppContext`: the injected collaborators (`sender` + `ChatStore`/`PersistentTaskQueue`/`LinkCache`/`Config`), `from_statics` for production and the `CONTEXT` static the worker closures hold. `test_support::TestStores` backs handler tests with a tempdir store set |
 | `crates/xmedia-bot/src/send/` | `send/mod.rs`: `Task`/`MediaItemPayload` payloads, `SendError`/`Classification`, `send_media_sequence`/`send_animation`/`forward_messages`; `send/input_media.rs`: payload → `InputFile`/`InputMedia` + `build_media_group` (caption on the first item only); `send/upload.rs`: the download-and-reupload fallback (`prepare_upload_item`/`send_batch_via_upload`, photo downscale handoff); `send/post_send.rs`: link-cache write, `KEEP_ALIVE` registry, `settle_task`, `post_send_actions`, `handle_task`/`dead_letter_notify` |
 | `crates/xmedia-bot/src/media_sender.rs` | `MediaSender` trait: the user-flow surface (`send_media_group`/`send_animation`/`copy_messages`/`send_message`/`answer_callback_query`/`edit_message_caption`/`delete_message`/`send_chat_action`) implemented by teloxide `Bot` (per-chat rate-limited) and by a recording `MockSender` in tests. Admin/setup APIs (`get_chat`, `set_my_commands`, …) stay on the concrete `Bot` |
@@ -105,9 +105,9 @@ Docker: `docker build -t tgxmb .` then `docker run --rm -d --name tgxmb --env-fi
 
 ## Testing & QA
 
-- **~200 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).
+- **~180 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/bilibili/interface.rs` (4), `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. `disabled_site_is_reported_not_ignored` (same file) is gated the other way round: it asserts `fetch` answers `FetchError::Disabled { site: "pixiv" }` for a pixiv link and early-returns when `PIXIV_REFRESH_TOKEN` **is** set (the site is then enabled). 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), and the bilibili live tests early-return when the API answers risk control (`-352`, which bilibili applies per IP by request volume). Run the full offline suite with `cargo test --workspace`.
+- Live-network tests exist in `site/twitter/interface.rs` (5), `site/bsky/interface.rs` (1), `site/misskey/interface.rs` (1), `site/bilibili/interface.rs` (5), `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. `disabled_site_is_reported_not_ignored` (same file) is gated the other way round: it asserts `fetch` answers `FetchError::Disabled { site: "pixiv" }` for a pixiv link and early-returns when `PIXIV_REFRESH_TOKEN` **is** set (the site is then enabled). 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), and the bilibili live tests early-return when the API answers risk control (`-352`, which bilibili applies per IP by request volume). 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` (actions pinned to commit SHAs, `--locked` on every cargo invocation, `concurrency` cancels superseded runs, `RUST_BACKTRACE=1`) runs `cargo fmt --check` + `cargo clippy --workspace --all-targets --locked -- -D warnings` + `cargo test --workspace --locked` + a release-profile `cargo build --release --locked` + an `actions-rust-lang/audit` dependency-vulnerability gate (offline, no secrets, on every push/PR) and a `live` job (schedule/manual/tag only, `-p x-media` since every network/secret-gated test lives there, `continue-on-error`) for the `#[ignore]`d live + token tests. `.github/workflows/docker.yml` builds and pushes the image on master/tag and runs a **build-only check on pull requests touching the build inputs** (`Dockerfile`, entrypoint, manifests, `.dockerignore`); a release tag must match both crate versions or the build stops, and `FFMPEG_URL`/`FFMPEG_SHA256` are taken from repository variables when set (a release can pin an exact ffmpeg build). `.github/dependabot.yml` keeps crates, the pinned actions and the Docker base images current.
 - Untested and hard to test without a mock seam: `main.rs`, `config.rs`, `db.rs`, `handlers/statics.rs`, `media_sender.rs` (holds the `MockSender` itself); in `x-media`: `media.rs`, `lib.rs`, all `model.rs`. The `commands.rs` *executor* needs a real `Bot` (only its pure report builder is tested). Everything else — `handlers/{mod,callback,inline,urls}.rs`, `send/*`, `ctx.rs`, `state.rs`, `queue.rs`, `link_cache.rs`, `rate_limit.rs` — is driven through `TestStores`/`ctx::test_support` and the scripted `MockSender`.