feat: document & audio corpus picker for all tools

- Add "Select from My Docs" button to all text tool forms; free-tier
  users see an upgrade modal, paid (CaveauAI) users get a searchable
  multi-select modal backed by /api/dashboard/documents.php
- Add "Select from My Audio" picker on Transcribe with single-select
  and a "Save to My Audio" button for persisting uploaded clips
- New PHP helpers in bootstrap.php: dbnToolsFetchDocChunks,
  dbnToolsClientIdFromSession, dbnToolsInjectDocContent
- timeline, ask, redact APIs prepend selected document content
  (fetched from client_chunks SQL) before the textarea text
- api/dashboard/audio-upload.php stores audio files on server and
  creates a client_documents row with source_type='audio'
- api/transcribe.php falls back to stored audio via audio_doc_id POST
  field when no file is uploaded
- api/dashboard/documents.php supports ?source_type= filter
- tools.js: doc_ids added to JSON payload; stored-audio transcribe path
- New assets/css/doc-picker.css, assets/js/doc-picker.js
- SQL migration: scripts/sql/audio_docs_column.sql

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/js/tools.js

@@ -1070,13 +1070,17 @@ async function runTool(event) {
 
   const tool = tools[state.activeTool];
   const text = els.input.value.trim();
-  if (!text) {
-    els.status.textContent = 'Add text before running the tool.';
-    els.input.focus();
+  const docIds = (document.getElementById('docPickerIds')?.value || '')
+      .split(',').map(Number).filter(Boolean);
+
+  if (!text && !docIds.length) {
+    els.status.textContent = 'Add text or select a document before running the tool.';
+    if (!docIds.length) els.input.focus();
     return;
   }
 
   const payload = { [tool.payloadKey]: text };
+  if (docIds.length) payload.doc_ids = docIds;
   if (tool.usesLanguage) {
     payload.language = currentLanguage();
   }
@@ -1812,6 +1816,45 @@ function showTranscribeProgress(clip, total) {
 }
 
 async function runTranscribe() {
+  const storedAudioDocId = parseInt(document.getElementById('audioPickerDocId')?.value || '0', 10);
+
+  // Stored audio path — no file in the queue required
+  if (storedAudioDocId > 0 && !audioQueue.length) {
+    setBusy(true);
+    els.status.textContent = 'Transcribing from corpus…';
+    try {
+      const fd = new FormData();
+      fd.append('audio_doc_id', String(storedAudioDocId));
+      fd.append('language', currentTranscribeLang ? currentTranscribeLang() : 'auto');
+      fd.append('task', currentTask ? currentTask() : 'transcribe');
+      const vadFilter = document.getElementById('vadFilterCheck')?.checked ?? false;
+      if (vadFilter) fd.append('vad_filter', '1');
+      const initPrompt = (document.getElementById('initPromptInput')?.value || '').trim();
+      if (initPrompt) fd.append('initial_prompt', initPrompt);
+      const whisperModel = document.getElementById('whisperModelSelect')?.value;
+      if (whisperModel) fd.append('model', whisperModel);
+      const postModel = document.querySelector('input[name="post_model"]:checked')?.value;
+      if (postModel) fd.append('post_model', postModel);
+      const diarize = document.getElementById('diarizeCheck')?.checked ?? false;
+      if (diarize) {
+        fd.append('diarize', '1');
+        const ns = parseInt(document.getElementById('numSpeakersInput')?.value || '', 10);
+        if (ns >= 2) fd.append('num_speakers', String(ns));
+      }
+      const resp = await fetch('api/transcribe.php', { method: 'POST', credentials: 'same-origin', body: fd });
+      const data = await resp.json().catch(() => ({}));
+      if (!resp.ok || !data.ok) throw new Error(data.error?.message || 'Transcription failed.');
+      if (typeof renderTranscribeResult === 'function') renderTranscribeResult(data);
+      else renderResults(data);
+      els.status.textContent = 'Done.';
+    } catch (err) {
+      els.status.textContent = err.message;
+    } finally {
+      setBusy(false);
+    }
+    return;
+  }
+
   if (!audioQueue.length) {
     els.status.textContent = currentUiT('noFileSelected');
     return;