perf: rest animations, cheaper chat typing and server polls, async per-tool hooks

UI
- No animation runs forever: Sagi moods, the custom pet sprite, status dots
  (pulse-dot, pulse-slow, ping) and the chat shimmer play a few cycles and
  rest. An infinite animation kept the browser drawing 60 frames a second.
- useSagiBrain: frames that only move lastActivityAt by <1 s keep the old
  state; the 1 s tick re-renders only when the mood changes.
- ConversationView and MessageList are memoized and PaneChat passes stable
  callbacks: typing in the chat box no longer re-renders the conversation.
- The chat's 700 ms menu poll reads plain text first and scans the terminal
  cell by cell (reusing one cell) only when a row could be a menu cursor row.

Server
- GET /sessions/:id/transcript?after=N skips lines <= N before JSON.parse.
- GET /sessions/:id/outline is cached until the session's events change.
- broadcastLane uses the cached tmux.liveSessions(); tmux.hasSession answers
  "yes" from the fresh shared list instead of a synchronous spawn (50-150 ms
  per psmux call on Windows, blocking terminal echo).
- pane-mode polls every 150 ms; writeHourly writes only changed hour buckets.
- /api/metrics: agenthub_event_loop_delay_seconds{quantile}.

Hooks
- PreToolUse/PostToolUse run with "async": true (settings installer,
  plugin.json, S3 managed settings): Claude Code no longer waits a Node start
  before and after every tool call.

Committed with --no-verify at the owner's request: the pre-commit full server
suite fails on 9 tests that fail identically on 0c2f498 (lane-sync merge: no
git identity on this host; read-pool; resolveHost; codex-usage 1 ms flake).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/routes/settings.js

@@ -11,6 +11,7 @@ const v8 = require("v8");
 const { db, stmts, DB_PATH, DEFAULT_PRICING, applyIntroPricing } = require("../db");
 const { getConnectionCount } = require("../websocket");
 const { transcriptCache } = require("./hooks");
+const { forgetHourly } = require("../lib/hourly-usage");
 
 const router = Router();
 
@@ -179,6 +180,7 @@ router.post("/clear-data", (_req, res) => {
 function clearAll() {
   db.prepare("DELETE FROM token_usage").run();
   db.prepare("DELETE FROM token_usage_hourly").run();
+  forgetHourly();
   db.prepare("DELETE FROM events").run();
   db.prepare("DELETE FROM agents").run();
   db.prepare("DELETE FROM sessions").run();
@@ -782,6 +784,7 @@ router.post("/cleanup", (req, res) => {
         db.prepare(`DELETE FROM token_usage_hourly WHERE session_id IN (${placeholders})`).run(
           ...chunk
         );
+        forgetHourly(chunk);
         db.prepare(`DELETE FROM sessions WHERE id IN (${placeholders})`).run(...chunk);
       }
       result.purged_sessions = ids.length;