fix: chat evaluation bugs — task pipeline, prompt grounding, markdown rendering

Addresses 14 bugs from 3 rounds of deep chat evaluation:

- Add chat-to-task pipeline in agents.py with regex-based intent detection,
  agent extraction, priority extraction, and title cleaning
- Filter meta-questions ("how do I create a task?") from task creation
- Inject real-time date/time context into every chat message
- Inject live queue state when user asks about tasks
- Ground system prompts with agent roster, honesty guardrails, self-knowledge,
  math delegation template, anti-filler rules, values-conflict guidance
- Add CSS for markdown code blocks, inline code, lists, blockquotes in chat
- Add highlight.js CDN for syntax highlighting in chat responses
- Reduce small-model memory context budget (4000→2000) for expanded prompt
- Add 27 comprehensive tests covering the full chat-to-task pipeline

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

static/style.css

@@ -429,6 +429,44 @@ a:hover { color: var(--orange); }
 .chat-message.agent     .msg-body { border-left: 3px solid var(--purple); }
 .chat-message.error-msg .msg-body { border-left: 3px solid var(--red); color: var(--red); }
 
+/* ── Markdown rendering in Timmy chat ─────────────────── */
+.timmy-md { white-space: normal; }
+.timmy-md p { margin: 0 0 0.5em; }
+.timmy-md p:last-child { margin-bottom: 0; }
+.timmy-md pre {
+  background: #0d0620;
+  border: 1px solid var(--border);
+  border-radius: var(--radius-sm);
+  padding: 10px 12px;
+  overflow-x: auto;
+  margin: 0.5em 0;
+  white-space: pre;
+}
+.timmy-md code {
+  font-family: var(--font);
+  font-size: 0.9em;
+}
+.timmy-md :not(pre) > code {
+  background: rgba(168, 85, 247, 0.15);
+  padding: 2px 5px;
+  border-radius: 3px;
+  color: var(--text-bright);
+}
+.timmy-md ul, .timmy-md ol { padding-left: 1.5em; margin: 0.4em 0; }
+.timmy-md blockquote {
+  border-left: 3px solid var(--purple);
+  padding-left: 10px;
+  color: var(--text-dim);
+  margin: 0.5em 0;
+}
+.timmy-md h1, .timmy-md h2, .timmy-md h3 {
+  color: var(--text-bright);
+  margin: 0.6em 0 0.3em;
+  font-size: 1em;
+  font-weight: 700;
+}
+.timmy-md a { color: var(--purple); }
+
 /* Mobile chat classes (used by mobile.html) */
 .chat-container {
   overflow-y: auto;