feat(web): "read her mind" — live self-state page

A pull-up-anytime view of Lyra's interiority, so her thoughts aren't buried in
a DB blob. Mobile-first, auto-refreshing every 12s (and on tab focus).

- GET /self serves the page; GET /self/state returns her self-state + the
  timestamp it last changed
- shows: current mood + feeling meters (valence/energy/confidence/curiosity),
  her drives as bars, her self-narrative, the relationship line, and the
  reflections list (newest first), plus cycle/reflection counters and "last
  cycle Xm ago"
- memory.self_state_updated_at(): when her mind last changed
- index.html: "🧠 Mind" button opens /self

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lyra/web/static/index.html

@@ -70,6 +70,7 @@
       <button id="renameSessionBtn">✏️ Rename</button>
       <button id="thinkingStreamBtn" title="Show live activity log">📜 Live Log</button>
       <a id="fullLogBtn" href="/logs" target="_blank" rel="noopener" title="Open the full-page log" role="button">⛶ Full Log</a>
+      <a id="mindBtn" href="/self" target="_blank" rel="noopener" title="Read her mind — Lyra's current self-state" role="button">🧠 Mind</a>
     </div>
 
     <!-- Status -->