# Worklog — AVA (Advanced Visualization Agent) Project: Audio-reactive visualization agent (AVS-style scripting, 3-band spectrum detection, predictive beat tracking). Built as a Next.js 16 web app (reference implementation) plus a Rust/Vulkan scaffold for the future native cross-platform export. User requirements: - 3-band detection: Bass 20–100 Hz, Mid 700 Hz–2 kHz, High 7 kHz–16 kHz (user-adjustable) - Beat detection from bass + beat PREDICTION (keeps beat when bass drops out) - Green dot beat indicator + "Set Beat" tap-tempo button - AVS-style custom visualization script editor: edit, save as default, save to file, load from file - Help section with variables/functions reference - 5 preset scripts (user provided real Winamp AVS presets on Google Drive) - Rust + Vulkan target for Linux/Windows/macOS export (scaffold + blueprint delivered here) --- Task ID: 1 Agent: main (Z.ai Code) Task: Project inspection + Google Drive preset retrieval Work Log: - Verified dev server running on port 3000 (Next.js 16.1.3, dev.log clean) - Fetched Google Drive folder (public) — extracted 5 file IDs and downloaded all files: - "Synth-C - Gap The Mind.avs" (12.5 KB) - "zamuz - wonder 'bout.avs" (34 KB) - "Synth-C - Quantization.avs" (14.8 KB) - "zamuz - keep tryin'.avs" (19 KB) - "zamuz - vorticity (brain activity remix).avs" (17 KB) - Parsed binary AVS format (null-terminated strings): extracted Superscope code, Texer II configs, movement expressions. These are scene classics from visbot.net. - Decided engine design: AVS-eel-flavored expression language (if/above/below/equal/rand, getspec/getosc-equivalents sv/v, reg-free flat variables) so the presets port naturally. Stage Summary: - All 5 original presets secured and understood; will be adapted to the AVA script dialect (originals preserved as downloadable files in public/avs-originals/). - Core engine architecture defined: expression compiler, script parser, BeatTracker (PLL-style predictor + tap tempo), AudioEngine (WebAudio FFT, mic/file/demo synth), canvas renderer. --- Task ID: 2 Agent: main (Z.ai Code) Task: Project setup — deps, Prisma schema, DB, original preset files Work Log: - Installed jszip (for the Rust scaffold zip download API) - Prisma schema rewritten: `Preset` (name/author/description/content/isBuiltIn, unique name) and `Settings` (defaultScript + bandConfig + beatConfig JSON) — ran `bun run db:push` OK - Copied the 5 original Winamp .avs binaries to public/avs-originals/ (downloadable from UI) Stage Summary: - DB ready; jszip available; originals served at /avs-originals/*.avs --- Task ID: 3 Agent: main (Z.ai Code) Task: AVA core engine libraries (src/lib/ava/*) Work Log: - types.ts — BandConfig / BeatConfig / BandLevels / BeatFrame + defaults (bass 20–100 Hz, mid 700–2000 Hz, high 7000–16000 Hz as requested) - expression.ts — full expression compiler: tokenizer → recursive-descent parser → closure tree. AVS-eel flavored: if() is LAZY, && / || short-circuit, ternary, ^ power (right-assoc), assignment valid inside call args + ternary branches (if(cond, x=1, x=2) works), newline & ';' statement separators (newlines inside parens ignored), '#'/'//' comments, deterministic hash rand(seed). 30+ functions incl. above/below/equal/band/bor/bnot/frac. - script.ts — text format parser: header keys (name/author/description/mode/blend/persist/ linewidth) + [init]/[frame]/[beat]/[point] sections, error objects with section+line, validateScript() never throws. - beat.ts — BeatTracker: rolling-average energy detection w/ threshold+minInterval+floor, interval learning (median + EMA period lock, spread gating), PLL-style phase predictor that keeps firing beats when bass drops (confidence-gated, slowly decays), tap() tempo learning. - audio.ts — AudioEngine: WebAudio AnalyserNode FFT 8192 (~5.4 Hz bins), byte-spectrum band averaging with attack 35ms / release 220ms smoothing; sources: demo (synthesized techno: kick 160→43Hz sweep, snare bandpass 1.8k, hats HP 8.2k, saw bassline — audible + analyzable), mic (never routed to speakers), file (loops, audible). getWave/getSpectrum for scripts. - presets.ts — 5 built-in presets ADAPTED from the user's real AVS files: Gap The Mind (radial warp rings), wonder 'bout (bass-spawned expanding rings), Quantization (grid-snapped dot rings), keep tryin' (bass burst dots + swirl), vorticity (twisting spiral arms) + STARTER_TEMPLATE. - engine.ts — AvaEngine: rAF loop (bands → beat → env → frame/beat progs → point prog ×N → draw), canvas 2d renderer with additive blending, per-point color, 2-pass glow, persistence trails, lines/dots/solid modes, DPR-aware resize via ResizeObserver, throttled stats callback for the UI. Singleton via getEngine(). - SMOKE TESTED via bun script: all 5 presets parse & execute 120 frames; lazy-if/ternary/pow OK; beat sim locks 124.1 BPM from 124 BPM kick train; predictor sustains beats through 10s of silence; tap tempo locks 120 BPM from 500ms taps. (2 parser bugs found & fixed: assignment inside call args; newline statement separators with paren-awareness.) Stage Summary: - Core engine complete and verified. Env variables exposed to scripts: n, t, time, dt, frame, bass/mid/treb (+ _att), vol (+ _att), beat, bpm, beatphase, beatconf, beats, w, h, aspect, persist, i, v, sv, x, y, red, green, blue, skip, size, alpha. --- Task ID: 4 Agent: main (Z.ai Code) Task: API routes Work Log: - GET/POST /api/presets — GET seeds built-ins on first run and lists all; POST upserts user presets by name (built-ins protected, 409 on name clash with built-in) - PUT/DELETE /api/presets/[id] — user presets only - GET/PUT /api/settings — defaultScript + bandConfig + beatConfig (upsert, JSON strings in DB) - Created src/lib/ava/blueprint.ts STUB (interface Blueprint + placeholder) for Task 3-b Stage Summary: - Backend complete. Frontend contract: GET /api/presets → { presets: [...] }; POST /api/presets {name, content, author?, description?} → {preset}; GET /api/settings → { defaultScript, bandConfig, beatConfig }; PUT /api/settings { defaultScript? , bandConfig?, beatConfig? }. --- Task ID: 3-a Agent: full-stack-developer (UI) Task: Complete UI for AVA — single-page app (dark club/VJ aesthetic) with header (audio source controls, BPM readout, green beat dot + Set Beat pairing), visual stage (canvas + engine loop), 5-tab control panel (Presets / Script / Detect / Beat / Native) and sticky footer status bar. Work Log: - Read worklog + all engine APIs (types/engine/script/presets/blueprint/audio/beat) and the existing API routes before writing any code. - src/lib/store.ts — zustand store: throttled stats (AvaStats = EngineStats + beatCount), beatFlash pulses, bandConfig/beatConfig mirrors that write the engine live + persist (localStorage instant, PUT /api/settings debounced 600 ms with shape guards), preset list + refreshPresets(), script text, active tab. - src/components/ava/audio-source.ts — tapBeat() (engine.beat.tap + dot flash + lastTap), applyScriptText() (validate → setScript, engine.setScript), and useAudioSource() hook wrapping startDemo/startMic/startFile/stop with error mapping (mic permission / no device / decode failure → destructive toast) and store sync from engine.audio.kind (authoritative). - src/components/ava/beat-dot.tsx — the green indicator: SVG phase ring (stroke-dashoffset follows beat.phase, 150 ms linear transition), emerald dot that scales 1.9× + glows 180 ms on audio/tap beats, and for predicted beats an expanding outline ring (framer-motion, 450 ms) + "PRED" badge. Flash state is derived (seq vs clearedSeq) — no setState-in-effect. - src/app/page.tsx — useInitialLoad (presets + settings; server → localStorage → first preset → STARTER_TEMPLATE fallback chain; applies configs + script), useBeatWatcher (see decisions below), useSpaceToTap (Space outside inputs/textarea/select/button → tap, preventDefault). Root layout: min-h-screen flex-col, lg:h-screen with internal panel scroll (footer always at viewport bottom; mobile pushes footer naturally). - src/components/ava/header.tsx — sticky, backdrop-blur; emerald logo square + AVA title + subtitle (hidden on mobile); segmented Demo/Mic/File/Stop control (44 px targets, active state emerald, hidden file input); demo BPM slider (60–200, only while demo active); right cluster = BPM readout (mono, emerald, '—' when unknown) + BeatDot + Set Beat button, always visible, wraps to row 1 on mobile (source controls wrap to row 2). - src/components/ava/visual-stage.tsx — owns engine lifecycle (engine.start/ stop + onStats → store), idle glass overlay with 3 big source buttons (AnimatePresence fade), top-left FPS/PTS readout (pointer-events-none), top- right fullscreen toggle (requestFullscreen on container). Canvas absolute fill; engine's ResizeObserver handles DPR. - src/components/ava/presets-tab.tsx — preset cards (name/author/description line-clamp-3, mode + built-in/custom badges), Load (applies + toasts, jumps to Script tab on compile error), ".avs original" download link for built-ins via originalFileUrl(name), two-step Delete (3 s confirm timeout) for customs, "New Script" (STARTER_TEMPLATE + switch tab), save-as-preset section (POST, 409 handled, refresh + toast). List: max-h-96 + thin styled scrollbar. - src/components/ava/script-tab.tsx — toolbar (Apply ▶ / Save as Default 💾 / Save to File ⬇ Blob download .ava / Load from File 📂 (.ava,.avs, .txt, auto-applies when valid) / New / Help ?), gutter+textarea editor (synced scroll, Tab → 2 spaces, min-h-320, wrap=off), rose gutter line on the error line, live debounced validation (250 ms), status line "✔ Compiled OK — mode: lines, n=480" (n from running [init] on a scratch env) / compile error / stats.error runtime errors. - src/components/ava/help-panel.tsx — Quick Start, full variables table (frame + point-only), functions table, operators, 5 example formulas, .ava file format doc. - src/components/ava/detect-tab.tsx — Bass/Mid/High cards: Low/High Hz sliders (bass 10–300/20–500, mid 100–5000/300–8000, high 1000–12000/4000–20000; low < high enforced with min gaps 10/50/200 in the store), Gain 0.1–4, mono Hz readouts, live VU meters (instant fill emerald/amber/rose + _att peak-hold tick), per-band reset. - src/components/ava/beat-tab.tsx — 80 px BeatDot + source badge (AUDIO/PRED/ TAP), big BPM readout, large SET BEAT button (framer-motion whileTap), tap feedback ("Tap 3… keep tapping" → "Locked: 128.0 BPM"), confidence bar, beat count, sensitivity (threshold 1.1–2.5, "lower = more sensitive"), min interval 150–600 ms, prediction switch ("Keeps the beat alive when the bass drops out"), how-it-works explainer. - src/components/ava/native-tab.tsx — renders BLUEPRINT (title/intro/sections/ bullets/code blocks in scrollable pre), emerald "Download Rust Scaffold (.zip)" , identical-language note. - src/components/ava/footer-bar.tsx — sticky mt-auto status bar: SRC/FPS/PTS/ BPM/SCRIPT micro-stats (mono), green "engine ok" / pulsing red "script error". - src/app/layout.tsx — dark class on , title "AVA — Advanced Visualization Agent", body bg-zinc-950. - FIXED BUGS during browser testing: (1) Detect tab crashed — levels key for the high band is `treb` not `high` (added levelKey/attKey mapping to BandSpec); (2) lint: setState-in-effect in BeatDot (derived flash state instead); (3) lint: // text node in help panel. - Tuned src/hooks/use-toast.ts: TOAST_LIMIT 1→3, TOAST_REMOVE_DELAY 100 s→5 s (lingering toasts were covering header/panel buttons during testing). - VERIFIED in headless browser: initial load seeds presets + applies Gap The Mind (480 pts @60 fps); demo start/stop + DEMO slider; beat dot flashing live (scale 1↔1.9); tap tempo lock ("Locked: 119.9 BPM" from 4×500 ms taps, Space key too); after Stop the PRED badge/outline ring shows prediction carrying the beat; preset load/save/delete (two-step) round-trip via API; Save as Default → PUT /api/settings + localStorage; band slider → debounced PUT; .avs originals serve 200; script upload (auto-apply, n=300) + export to Upload Test.ava; mic error toast ("No microphone found" in this headless env); no blue/indigo anywhere; lint clean; tsc clean for owned files. Stage Summary: - Files created: src/lib/store.ts; src/components/ava/{shared.ts, audio-source.ts, beat-dot.tsx, header.tsx, visual-stage.tsx, presets-tab.tsx, script-tab.tsx, help-panel.tsx, detect-tab.tsx, beat-tab.tsx, native-tab.tsx, footer-bar.tsx, control-panel.tsx}. Modified: src/app/page.tsx (replaced), src/app/layout.tsx, src/hooks/use-toast.ts (toast duration/limit only). - KEY DECISION — beat flash sampling: engine stats are throttled (~8 Hz) but beat=true lasts one frame, so most beats are invisible in stats. The watcher in page.tsx ALSO fires on beat.phase running backwards (real beats reset phase to 0; the predictor grid wraps at 1). Classification: stats.beat.beat sampled → exact source; phase drop + prediction on + confidence > 0.35 + bassAtt < 0.06 → 'predicted'; phase drop + bassAtt > 0.05 → 'audio'; silent no-lock → no flash (idle dot doesn't pulse). Tap flashes suppressed for 300 ms to avoid double pulses. Verified working in-browser. - KEY DECISION — desktop uses lg:h-screen + internal panel scroll so the footer stays at the viewport bottom and the canvas fills the height; mobile uses natural flow (min-h-screen + mt-auto footer) so the footer is pushed down. - Store is the only place configs touch the engine (applyBandConfig/ setBandValue etc.), keeping live-update + persistence consistent everywhere. - NOTE for Task 5 (integration): /api/rust-scaffold is linked from the Native tab but the route does not exist yet (Task 3-b owns it — expect 404 until then). BLUEPRINT is still the stub; the Native tab renders whatever 3-b puts in it, no UI changes needed. Settings row 'main' currently holds defaultScript="Gap The Mind" + default bandConfig from testing (both equal defaults — safe to leave or clear). Pre-existing tsc errors in src/lib/ava/{audio,script}.ts and examples/ are NOT from this task (ignoreBuildErrors is set). --- Task ID: 3-b Agent: general-purpose (Rust scaffold + blueprint) — [timed out at the very end; deliverables verified complete by the main agent, which appends this entry] Task: Rust/Vulkan native-export scaffold + architecture blueprint + zip download API Work Log: - Built rust-agent/ cargo crate (ava-agent, edition 2021): winit 0.30 (ApplicationHandler API), wgpu 22 (Vulkan-first; `vulkan-force` feature for MoltenVK on macOS), cpal 0.15, rustfft 6.2, pollster, anyhow - src/audio.rs — cpal default-input capture, ring buffer, AudioProcessor::poll() per frame - src/spectrum.rs — Hann-window 8192 FFT, band levels w/ same attack(35ms)/release(220ms) smoothing as the web engine - src/beat.rs — 1:1 port of beat.ts (same constants, median+EMA lock, PLL predictor, taps) - src/script/{lexer,parser,env,mod}.rs — expression engine + .ava format parser with the same lazy-if / assignment-in-args / deterministic-rand semantics - src/engine.rs — script runtime host (init/frame/beat/point stepping, shared state) - src/render/{mod.rs,shader.wgsl} — wgpu pipelines: audio-reactive fullscreen background + additive point cloud, #[repr(C)] uniforms, persistence via TODO'd feedback texture - presets/*.ava — all six scripts (5 classics + starter) portable across engines - Rewrote src/lib/ava/blueprint.ts with 8 real sections (architecture map, wgpu/Vulkan strategy, audio pipeline, beat engine, script engine, rendering, per-platform builds, roadmap) - Built src/app/api/rust-scaffold/route.ts (jszip walk, skip target/.git/node_modules) Stage Summary: - Scaffold ~1,700 lines, all files present; zip route verified 200 in dev.log; lint clean. - NOT compiled (no cargo in sandbox) — scaffold quality, clearly TODO-marked where partial. --- Task ID: 5 Agent: main (Z.ai Code) Task: Integration, lint, agent-browser E2E verification & fixes Work Log: - bun run lint → zero errors across the whole project - dev.log clean: / 200, /api/presets 200, /api/settings 200, /api/rust-scaffold 200, no runtime errors, no hydration warnings - Agent-browser E2E golden path, all VERIFIED: * initial load: idle overlay, 5 preset cards + .avs original links, tabs render * Demo Track → canvas lit (30.7% pixels @60fps, 480 pts), footer SRC/FPS/PTS/BPM live * footer shows detected 120.0 BPM from the demo kick pattern * Set Beat ×4 taps → "Locked: 99.8 BPM" (matches real ~600ms tap intervals), confidence 65% * Beat tab: AUDIO badge, beat count, sensitivity ×1.40, min interval 250ms, prediction switch * Stop audio → badge switches to PRED, beat count 20→35 (predictor keeps the beat), confidence decays 65%→35% — core requirement verified * Script editor: broken script → "✘ [point] line 8: Unknown function 'badfunc'"; fixed script → "✔ Compiled OK — mode: lines, n=300" * Help panel: variables table, functions, operators, examples * Save as preset → "Smoke Test Ring" listed + toast; two-step delete verified * Save as Default → PUT /api/settings verified via curl; reload auto-loads the default * Detect tab: Bass 20–100 Hz / Mid 700–2000 Hz / High 7k–16 kHz cards, gains, live meters reading real audio (0.78/0.60/0.32) * Native tab: blueprint sections render + zip download (116 KB, 25 files, valid zip) * Mobile 390×844: responsive, footer pushed naturally, sticks to viewport bottom when scrolled - Cleanup: deleted the test preset, cleared test defaultScript (DB + localStorage) so a fresh visit loads "Gap The Mind" Stage Summary: - ALL acceptance criteria verified in-browser. Zero console errors. The application is fully interactive: 3-band detection, beat detection + prediction + tap learning, AVS-style scripting with editor/help/save/load, 5 authentic presets (adapted), Rust scaffold export. --- Task ID: 6 Agent: general-purpose Task: "Stream a link" backend — yt-dlp link resolution + same-origin audio byte proxy (POST /api/resolve, GET /api/audio/stream) Work Log: - Read worklog (Tasks 1–5) and existing routes; confirmed dev server already running on :3000 (Node, next-server v16.1.3) — never restarted it; no build, no new deps, no git - Installed yt-dlp standalone binary: bin/yt-dlp (GitHub latest yt-dlp_linux), chmod +x, --version prints 2026.10.21 - src/lib/server/ssrf.ts — assertPublicHttpUrl(raw): http(s) only, explicit port must be 80/443, localhost/.localhost/.local/.internal banned, IPv4 privates (0/8, 10/8, 100.64/10, 127/8, 169.254/16, 172.16/12, 192.168/16), IPv6 ::/::1/fc00::/7/fe80::/10 plus IPv4-mapped ::ffff:a.b.c.d (embedded v4 checked; hand-written IPv6 expander handles v4 tails + zone ids), then dns.promises.lookup(all:true) with EVERY result re-checked by the same rules (kills nip.io / DNS-rebind tricks). Throws user-safe messages; returns the parsed URL. - src/lib/server/stream-store.ts — Map on globalThis.__avaStreams via a typed interface with an optional property + `??=` (no `any`): token = randomBytes(16).hex (32 chars), entries { remoteUrl, title, source, expires }, 30-min sliding TTL, prune-on-every-access; exports createStreamEntry / getStreamEntry / refreshStreamEntry. - src/app/api/resolve/route.ts — JSON body { url } (≤2048, trim) → 400s; SSRF gate → 400; 10-min success cache on globalThis.__avaResolveCache (repeat links replay instantly); direct-audio bypass for .mp3 .m4a .aac .ogg .oga .opus .wav .flac .mp4 .webm (source "direct", title = decoded last path segment, fallback hostname); otherwise yt-dlp -J --no-warnings --no-playlist --no-progress --socket-timeout 15 -f "bestaudio[protocol^=http]/bestaudio/best" with a 30 s kill → 504; non-zero exit → ANSI/control-stripped stderr tail (300 chars) → 422 ("Unsupported URL" gets its own message); stream URL pick = data.url ?? requested_formats[0].url ?? last http-protocol format; .m3u8/.mpd path or m3u8/mpd/dash protocol → 422 adaptive message; SSRF re-check on the RESOLVED stream URL (public CDNs like googlevideo pass) → 422 if not; title control-stripped + clamped 140 (fallback "Stream"), source = extractor_key|extractor|hostname lowercase, durationSec = numeric duration or null. - src/app/api/audio/stream/route.ts — token → entry (prune first) else 404; SSRF re-check of the stored remoteUrl; forwards the client Range header, Chrome UA, redirect follow, no-store; !ok → 502 `Upstream failed (HTTP n).`; content-type must be audio/*, video/*, application/octet-stream or application/ogg else 502 "Upstream did not return audio."; refreshes sliding TTL, then passes through the upstream status with content-type/-length/ -range/accept-ranges (only when upstream provided them) + Cache-Control: public, max-age=1800. - FIX found while testing: the upstream host intermittently RST/ETIMEDOUTs full (non-ranged) fetches — verified against raw node fetch (1/6 ETIMEDOUT) — added ONE immediate retry on network-level failure only (HTTP error statuses are never retried); after that: 2× full GET 200 audio/mpeg 8,945,229 bytes. - tsc --noEmit: zero errors in the new files (the project's 8 pre-existing errors are all in src/lib/ava, examples/, skills/, rust-scaffold — untouched). Stage Summary: - yt-dlp: /home/z/my-project/bin/yt-dlp, version 2026.10.21 (runtime order: $AVA_YTDLP → /bin/yt-dlp if existsSync → "yt-dlp" on PATH) - Files created (nothing else touched, no frontend files): bin/yt-dlp, src/lib/server/ssrf.ts, src/lib/server/stream-store.ts, src/app/api/resolve/route.ts, src/app/api/audio/stream/route.ts - Test 1 MUST-PASS direct MP3 (soundhelix Song-1): resolve → ok:true, source:"direct", title:"SoundHelix-Song-1.mp3"; full stream GET → 200 audio/mpeg 8,945,229 B (>1 MB; takes ~30 s because the origin throttles at ~300 KB/s — proxy adds ~0); Range 0-1023 → 206 with content-range "bytes 0-1023/8945229", accept-ranges, cache-control all verified - Test 2 MUST-PASS SSRF: http://127.0.0.1/x → 400, http://169.254.169.254/latest/meta-data → 400, ftp://example.com/a.mp3 → 400. Extras: localhost:8080 → 400 (port), foo.bar.local → 400, [::1] → 400, [::ffff:10.0.0.5] → 400 (v4-mapped), 127.0.0.1.nip.io → 400 (DNS-result check), "not a url" / {} / {"url":5} / bad JSON → 400 "Expected { url } JSON body." - Test 3 YouTube jNQXAC9IVRw: bot-blocked from this datacenter IP ("Sign in to confirm you're not a bot"). Tried the 2 extractor-args variants (youtube:player_client=web_embedded, then =tv) within the 5-minute budget — still blocked. Surfaces as a clean 422 with the sanitized tail: "Could not extract audio from that link: …Sign in to confirm you're not a bot…". Honest outcome: blocked here, ACCEPTABLE per spec (would work from residential IPs / with cookies). - Test 4 SoundCloud forss/flickermood: yt-dlp extracts fine (title "Flickermood", 213.9 s) but this serve only exposes m3u8_native formats (hls_aac_96k/160k — confirmed in raw -J JSON) → clean 422 adaptive(HLS/DASH) message, exactly the manifest-only contract case. - Test 5 https://example.com/ → clean 422 "That site is not supported — try YouTube, SoundCloud, or a direct MP3 link."; example.com/stream.m3u8 → 422 (does NOT hit the direct bypass). - Extractor SUCCESS path proven end-to-end with archive.org: resolve → ok:true, title:"mp3 test file", source:"archiveorg", durationSec:12.42; stream → 200 audio/mpeg 198,658 B + 206 ranged; cache replay 16 ms. - Stream negatives: unknown/missing token → 404 "Unknown or expired stream token"; upstream 500 (missing file) → 502 "Upstream failed (HTTP 500)." - lint: my 4 files pass eslint clean; `bun run lint` overall reports exactly 1 remaining error in src/components/ava/link-dialog.tsx:72 (set-state-in-effect) — that file is owned by the parallel frontend agent and was NOT touched by me per the ownership rules. - dev.log: no exceptions/stack traces from the new routes — only expected 200/206/400/404/422/502 request lines. - Deviations from spec (all deliberate): (1) one network-error retry in the proxy (upstream RSTs, never retries HTTP statuses); (2) third store helper refreshStreamEntry() — the two required helpers plus this one implements the specified "refresh sliding expiry AFTER upstream success"; (3) proxy fetch uses cache:'no-store'; (4) 500 wording "Audio extractor unavailable (yt-dlp not found or failed to start)."; (5) success cache keyed by the normalized URL href (target.href). --- Task ID: 7 Agent: main (Z.ai Code) Task: Frontend integration of the "Link" audio source (YouTube / SoundCloud / direct MP3) Work Log: - Read worklog + all relevant files (audio.ts, store.ts, audio-source.ts, header.tsx, visual-stage.tsx, footer-bar.tsx, types.ts) before editing. - src/lib/ava/types.ts — AudioSourceKind += 'link' - src/lib/ava/audio.ts — new startUrl(streamUrl, title): same-origin proxied