feat(career): career plugin — stars, venue tiers, pack downloads (career mode 2/3) (#907)

* feat(career): career plugin — stars from song_stats, venue tiers, pack downloads (career mode PR2)

Bundled plugin: per-song stars from best_accuracy (60/75/85% → 1/2/3★),
cumulative stars unlock bar → club → arena (data-driven venues.json).
Venue packs (UE-rendered crowd loops) download on demand to
CONFIG_DIR/plugin_uploads/career/ on a background thread with sha256 +
zip-slip validation, served via FileResponse. Career screen (promoted
sidebar entry) shows progress and pushes the active venue's manifest
into the crowd video layer (v3VenueCrowd, PR1) — degrades cleanly when
either side is absent. Pack URLs land in venues.json in PR3.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(career): keep manifest cleanup path alive on delete; badge only for installed venues

Codex preflight: nulling _appliedManifestVenue on delete skipped
pushCrowdManifest's setManifest(null) cleanup, leaving the crowd layer on
a deleted pack; and the 'playing here' badge showed for an override venue
whose pack was removed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(career): generation-guard in-flight manifest fetches

Codex preflight: a manifest fetch resolving after a newer refresh (pack
deleted, venue switched) could re-apply a stale pack over the user's
newer selection — fetches now carry a generation token and bail when
superseded.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(career): exclude orphaned song_stats from star totals

Codex preflight: scans hide rather than delete stats of removed songs, so
stars now apply the same existing-song filter other stats surfaces use
(filename IN (SELECT filename FROM songs)).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(career): 50/150 star thresholds + star collection overview

Byron's progression tuning: club at 50★, arena at 150★. /state now
returns star_detail rows (title/artist joined from the library, stars,
best accuracy, next-star threshold) sorted closest-to-next-star first,
and the career screen renders a collection panel: tier summary plus a
per-song list with a 'N% to next star' practice hint.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(career): venue select/unselect UX, intro manifest support, fullmatch guards

- 'Play here' now also defaults the visualization to Venue (remembering
  the prior viz); active venues show 'Leave venue' which restores it and
  sets the '__none__' override so no installed venue silently reapplies.
- Pack manifests may ship an intro block (flyover video + ambience mp3);
  files validate like loops/stingers, .mp3 added to the serving whitelist.
- Codex preflight: whitelist regexes use fullmatch (trailing-newline names
  could validate but 500 on serving).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(career): let pushCrowdManifest clear the manifest on Leave venue

Codex preflight: nulling _appliedManifestVenue before refresh skipped the
setManifest(null) cleanup branch, leaving the crowd playing.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(career): refresh tailwind output

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

tests/js/career_plugin.test.js

@@ -0,0 +1,50 @@
+'use strict';
+
+const { test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const ROOT = path.join(__dirname, '..', '..');
+const PLUGIN_DIR = path.join(ROOT, 'plugins', 'career');
+const SHELL_JS = path.join(ROOT, 'static', 'v3', 'shell.js');
+
+test('career plugin manifest is complete and bundled', () => {
+    const manifest = JSON.parse(fs.readFileSync(path.join(PLUGIN_DIR, 'plugin.json'), 'utf8'));
+    assert.equal(manifest.id, 'career');
+    assert.equal(manifest.bundled, true);
+    assert.equal(manifest.screen, 'screen.html');
+    assert.equal(manifest.script, 'screen.js');
+    assert.equal(manifest.routes, 'routes.py');
+    for (const f of ['screen.html', 'screen.js', 'routes.py', 'venues.json', manifest.styles]) {
+        assert.ok(fs.existsSync(path.join(PLUGIN_DIR, f)), `${f} missing`);
+    }
+});
+
+test('venues.json defines the 3 ascending tiers with star thresholds', () => {
+    const content = JSON.parse(fs.readFileSync(path.join(PLUGIN_DIR, 'venues.json'), 'utf8'));
+    assert.deepEqual(content.star_accuracy_thresholds, [0.6, 0.75, 0.85]);
+    const venues = content.venues;
+    assert.deepEqual(venues.map((v) => v.id), ['bar', 'club', 'arena']);
+    assert.equal(venues[0].star_threshold, 0, 'bar must always be unlocked');
+    for (let i = 1; i < venues.length; i++) {
+        assert.ok(venues[i].star_threshold > venues[i - 1].star_threshold,
+            'thresholds must ascend');
+    }
+});
+
+test('shell promotes the career plugin into the sidebar', () => {
+    const src = fs.readFileSync(SHELL_JS, 'utf8');
+    assert.match(src, /key: 'career',\s*screen: 'plugin-career'/);
+    assert.match(src, /navKey: 'career',\s*pluginId: 'career',\s*slotId: 'v3-nav-career'/);
+});
+
+test('career screen pushes the crowd manifest with a base URL', () => {
+    const src = fs.readFileSync(path.join(PLUGIN_DIR, 'screen.js'), 'utf8');
+    assert.match(src, /v3VenueCrowd/);
+    assert.match(src, /setManifest\(manifest\)/);
+    assert.match(src, /manifest\.base = /);
+    assert.match(src, /feedBack-career-venue/);
+    // Degrades without the crowd layer (PR1 not merged / older desktop).
+    assert.match(src, /typeof crowd\.setManifest !== 'function'\) return/);
+});