feat: audit log, usage tracking UI, OpenAI orchestrator compaction, onboarding + docs

Tool audit log:
- Every orchestrator tool call logged to home/{user}/tool_audit/YYYY-MM-DD.jsonl
- Files panel sidebar: audit log group (collapsed), date-linked read-only table
- Admin endpoints: /api/audit/files, /api/audit/day, /api/audit/recent, /api/audit/stats
- Engine and model name recorded per entry

OpenAI orchestrator improvements:
- Context budget enforcement: 75% of model context_k (min 16k)
- Message compaction: truncates old tool results when approaching budget
- max_rounds respected per model config (intersected with server cap)

OpenRouter onboarding (setup.html, onboarding.py, app.js, settings.html):
- Step 3 of 3: /setup/model with curated model picker
- Chat banner for users on server-default model (informational, not alarmist)
- Settings quick-link card; /setup/model works standalone for existing users

Model registry + session store:
- set_role_config / get_role_config for per-role tool lists and system_append
- session_store: session rename, session name backfill endpoint

UI updates (app.js, index.html, style.css, local_llm.html):
- Role toggle in context panel
- Off-the-record mode
- Agent notes read-only viewer
- OPERATIONS.md loaded at T2+ in context

Documentation:
- HELP.md: full tool table, per-role tool sets, Agent Notes, usage tracking
- TOOLS.md: Agent Notes section, count corrected to 44
- ARCH__SYSTEM.md, ARCH__BACKENDS.md, MASTER.md updated to match reality
- CLAUDE.md: onboarding flow, documentation philosophy sections
- README.md: stack in practice, DeepSeek TUI mention, architecture diagram updated
- TODO__Agents.md: onboarding task completed with deviation notes

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

cortex/static/app.js

@@ -18,6 +18,11 @@
         const settings_dd_el     = document.getElementById('settings-dropdown');
         const sessionsBackdrop   = document.getElementById('sessions-backdrop');
 
+        // ── Utilities ─────────────────────────────────────────────────
+        function escapeHtml(str) {
+            return String(str).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;');
+        }
+
         // ── Close all panels/dropdowns (mutual exclusion) ─────────────
         function closeAllPanels() {
             if (mode_dropdown_el)  mode_dropdown_el.classList.remove('open');
@@ -435,8 +440,32 @@
             availableRoles = d.available_roles || [];
             roleIdx        = 0;
             setRoleToggleUI(availableRoles[0] || null);
+            _maybeShowNoBanner(availableRoles);
         });
 
+        function _maybeShowNoBanner(roles) {
+            const key = 'cx_no_model_banner_dismissed';
+            if (roles.length > 0) { localStorage.removeItem(key); return; }
+            if (localStorage.getItem(key)) return;
+            const banner = document.createElement('div');
+            banner.id = 'no-model-banner';
+            banner.style.cssText = [
+                'background:#1c1a0a','border-bottom:1px solid #78350f',
+                'color:#fbbf24','font-size:0.82rem','padding:0.55rem 1rem',
+                'display:flex','align-items:center','gap:0.75rem','flex-shrink:0',
+            ].join(';');
+            banner.innerHTML = `
+                <span style="flex:1">⚡ Using server default model — add your own for more choices and to track your usage.</span>
+                <a href="/setup/model" style="color:#fbbf24;font-weight:600;white-space:nowrap;">Set up OpenRouter →</a>
+                <button onclick="localStorage.setItem('${key}','1');document.getElementById('no-model-banner').remove();"
+                        style="background:none;border:none;color:#78350f;cursor:pointer;font-size:1rem;line-height:1;padding:0 0.2rem;"
+                        title="Dismiss">✕</button>
+            `;
+            // Insert at the top of #chat-col (or body if not found)
+            const col = document.getElementById('chat-col') || document.body.firstElementChild;
+            col.insertBefore(banner, col.firstChild);
+        }
+
         backendToggle.addEventListener('click', () => {
             if (availableRoles.length <= 1) return;
             roleIdx = (roleIdx + 1) % availableRoles.length;
@@ -1067,6 +1096,19 @@
                             sessionId = data.session_id;
                             sessionEl.textContent = `session: ${sessionId}`;
                             persist_session();
+
+                            // Auto-name the session from the first user message
+                            if (wasNewSession) {
+                                const autoName = text.slice(0, 60).trimEnd() + (text.length > 60 ? '…' : '');
+                                fetch(`/sessions/${sessionId}?${_fileParams}`, {
+                                    method: 'PATCH',
+                                    headers: { 'Content-Type': 'application/json' },
+                                    body: JSON.stringify({ name: autoName }),
+                                }).then(() => {
+                                    sessionEl.textContent = `session: ${autoName}`;
+                                    sessionNames.set(sessionId, autoName);
+                                }).catch(() => {});
+                            }
                             thinkingDiv.className = 'message assistant';
                             setMessageText(thinkingDiv, 'assistant', data.response);
                             const assistHistIdx = currentHistory.length;
@@ -1133,6 +1175,8 @@
             const text = inputEl.value.trim();
             if (!text || activeController) return;
 
+            const wasNewSession = !sessionId;
+
             inputEl.value = '';
             syncHeight();
             sendBtn.style.display = 'none';
@@ -1357,6 +1401,7 @@
             { label: 'Memory',   files: ['MEMORY_LONG.md', 'MEMORY_MID.md', 'MEMORY_SHORT.md'] },
             { label: 'Profile',  files: ['USER.md', 'HELP.md'] },
             { label: 'Settings', files: ['email_allowlist.json'] },
+            { label: 'Agent Notes (read-only)', files: ['AGENT_NOTES.bak1.md', 'AGENT_NOTES.bak2.md', 'AGENT_NOTES.bak3.md'], collapsed: true },
         ];
 
         function fmtSize(bytes) {
@@ -1394,7 +1439,7 @@
             fileSidebar.innerHTML = '';
 
             for (const group of FILE_GROUPS) {
-                const { groupEl, items } = _makeFileGroup(group.label);
+                const { groupEl, items } = _makeFileGroup(group.label, group.collapsed || false);
 
                 for (const fname of group.files) {
                     const f = byName[fname];
@@ -1490,12 +1535,20 @@
             // Restore editor/preview buttons hidden by audit view
             fileRawBtn.style.display = '';
             filePreviewBtn.style.display = '';
-            fileSaveBtn.style.display = '';
             const res = await fetch(`/files/${encodeURIComponent(name)}?${_fileParams}`);
             if (!res.ok) { mdEditor.setValue(`Error loading ${name}`); return; }
             const data = await res.json();
             mdEditor.setValue(data.content);
             mdEditor.clearHistory();
+            if (data.readonly) {
+                mdEditor.setOption('readOnly', 'nocursor');
+                fileSaveBtn.style.display = 'none';
+                document.getElementById('file-modal-title').textContent = name + ' (read-only)';
+            } else {
+                mdEditor.setOption('readOnly', false);
+                fileSaveBtn.style.display = '';
+                document.getElementById('file-modal-title').textContent = name;
+            }
             setFileMode(fileMode);
         }
 
@@ -1794,11 +1847,13 @@
         let memMid      = localStorage.getItem('mem-mid')   !== 'false';
         let memShort    = localStorage.getItem('mem-short') !== 'false';
 
+        const TIER_LABELS = { 1: 'Min', 2: 'Std', 3: 'Ext', 4: 'Full' };
+
         function updateTierUI() {
             document.querySelectorAll('.ctx-btn[data-tier]').forEach(btn => {
                 btn.classList.toggle('active', parseInt(btn.dataset.tier) === currentTier);
             });
-            ctxOpenBtn.querySelector('.tier-badge').textContent = currentTier;
+            ctxOpenBtn.querySelector('.tier-badge').textContent = TIER_LABELS[currentTier] || currentTier;
         }
 
         function updateMemUI() {
@@ -1870,33 +1925,46 @@
             memShort = !memShort; localStorage.setItem('mem-short', memShort); updateMemUI();
         });
 
+        const _distillBtns = () => document.querySelectorAll(
+            '#distill-short-btn, #distill-mid-btn, #distill-long-btn, #distill-all-btn, #distill-rebuild-btn'
+        );
+
         function showDistillStatus(msg, isErr) {
             distillStatus.textContent = msg;
             distillStatus.classList.toggle('err', !!isErr);
             distillStatus.classList.add('show');
-            setTimeout(() => distillStatus.classList.remove('show'), 5000);
+            setTimeout(() => distillStatus.classList.remove('show'), isErr ? 8000 : 5000);
         }
 
-        async function runDistill(endpoint) {
-            showDistillStatus('distilling…', false);
+        async function runDistill(endpoint, label) {
+            _distillBtns().forEach(b => { b.disabled = true; });
+            showDistillStatus(`${label || endpoint} running…`, false);
             try {
                 const res = await fetch(`/distill/${endpoint}?${_fileParams}`, { method: 'POST' });
                 const d = await res.json();
-                if (!res.ok || d.ok === false) {
-                    const err = d.error || d.mid?.error || d.long?.error || `HTTP ${res.status}`;
+                if (res.status === 409 || res.status === 429) {
+                    showDistillStatus(`⏳ ${d.detail}`, true);
+                } else if (!res.ok || d.ok === false) {
+                    const err = d.detail || d.error || d.mid?.error || d.long?.error || `HTTP ${res.status}`;
                     showDistillStatus(`✗ ${err}`, true);
                 } else {
-                    showDistillStatus(`✓ ${endpoint} done`, false);
+                    showDistillStatus(`✓ ${label || endpoint} complete`, false);
                 }
             } catch (err) {
                 showDistillStatus(`✗ ${err.message}`, true);
+            } finally {
+                _distillBtns().forEach(b => { b.disabled = false; });
             }
         }
 
-        document.getElementById('distill-short-btn').addEventListener('click', () => runDistill('short'));
-        document.getElementById('distill-mid-btn').addEventListener('click',   () => runDistill('mid'));
-        document.getElementById('distill-long-btn').addEventListener('click',  () => runDistill('long'));
-        document.getElementById('distill-all-btn').addEventListener('click',   () => runDistill('all'));
+        document.getElementById('distill-short-btn').addEventListener('click', () => runDistill('short', 'Short distill'));
+        document.getElementById('distill-mid-btn').addEventListener('click',   () => runDistill('mid',   'Mid distill'));
+        document.getElementById('distill-long-btn').addEventListener('click',  () => runDistill('long',  'Long distill'));
+        document.getElementById('distill-all-btn').addEventListener('click',   () => runDistill('all',   'Full distill'));
+        document.getElementById('distill-rebuild-btn').addEventListener('click', () => {
+            if (!confirm('Rebuild memory from scratch?\n\nThis will wipe MEMORY_MID and MEMORY_LONG (backups kept) then regenerate them from session logs. Any hand-edited content will be replaced.\n\nContinue?')) return;
+            runDistill('rebuild', 'Memory rebuild');
+        });
 
         updateTierUI();
         updateMemUI();