Fix drift sync: per-window verdicts, forgiving class match, event-driven status bar

Three independent defects made the focus state feel flaky and let the OS
status bar disagree with the web UI:

- Status file lagged the web by up to a minute: it rendered only on a 60s
  ticker with no hook into state changes. notify() now fans out to multiple
  listeners (AddOnChange) and the writer has a coalesced Wake() so drift
  reaches the bar as promptly as the browser.

- A brief off-task visit could latch drift for the whole session. Sibling
  windows of one app (a browser's reading tab vs its chat tab) share a window
  class, but the judge verdict was cached by class alone, so one tab's verdict
  poisoned the rest and never re-judged. Cache is now keyed by class + scrubbed
  title (judgedWindows) so siblings are judged independently.

- Allowed-class matching was exact equality, so a short token ("brave") never
  matched the real WM_CLASS ("Brave-browser") and every window was routed to
  the LLM. Matching is now substring-based, and planning surfaces the live
  window class with a click-to-add chip so users pick a token that matches.

Also fix the planning checkbox alignment: the global full-width input rule was
stretching the "Enforce focus" checkbox; scope it out for checkboxes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

internal/session/drift.go

@@ -76,15 +76,15 @@ func (c *Controller) resetDriftLocked() {
 	c.driftGen++
 	c.nudgeEpoch++
 	c.lastJudgedAt = time.Time{}
-	c.judgedClasses = map[string]ai.Verdict{}
+	c.judgedWindows = map[string]ai.Verdict{}
 	c.recentTitles = nil
 	c.nudgeMessage = ""
 	c.lastNudgedAt = time.Time{}
 }
 
 // OnTask appends the current window class to the session allowed-context, clears
-// drift, drops any cached verdict for that class, and persists. The class now
-// matches locally and is never re-judged.
+// drift, drops the cached verdict for the current window, and persists. The
+// class now matches locally and is never re-judged.
 func (c *Controller) OnTask() error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -100,7 +100,7 @@ func (c *Controller) OnTask() error {
 		if !evidence.MatchesAllowed(ac, class, "") {
 			c.allowedClasses = append(c.allowedClasses, strings.TrimSpace(class))
 		}
-		delete(c.judgedClasses, class)
+		delete(c.judgedWindows, verdictKey(class, c.stats.Current.Title))
 	}
 	c.driftStatus = driftOnTask
 	c.driftReason = ""
@@ -108,7 +108,7 @@ func (c *Controller) OnTask() error {
 }
 
 // Refocus clears the current drift verdict without changing allowed-context, and
-// drops the cached verdict for the current class so it may be judged again later.
+// drops the cached verdict for the current window so it may be judged again later.
 func (c *Controller) Refocus() error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -116,7 +116,7 @@ func (c *Controller) Refocus() error {
 		return ErrNotActive
 	}
 	if c.stats != nil {
-		delete(c.judgedClasses, c.stats.Current.Class)
+		delete(c.judgedWindows, verdictKey(c.stats.Current.Class, c.stats.Current.Title))
 	}
 	c.driftStatus = driftIdle
 	c.driftReason = ""
@@ -193,8 +193,12 @@ func (c *Controller) evaluateDriftLocked(now time.Time, snap evidence.WindowSnap
 	c.nudgeMessage = ""
 	c.nudgeEpoch++
 
-	// 2. Per-class cache.
-	if v, ok := c.judgedClasses[class]; ok {
+	// 2. Per-window cache, keyed by class+title. A verdict for one window of an
+	// app must not leak to a sibling window of the same class — a browser hosts
+	// both an on-task reading page and an off-task chat under one window class, so
+	// keying by class alone latched one tab's verdict onto every other tab.
+	key := verdictKey(class, title)
+	if v, ok := c.judgedWindows[key]; ok {
 		c.applyVerdictLocked(v)
 		return nil
 	}
@@ -241,9 +245,9 @@ func (c *Controller) evaluateDriftLocked(now time.Time, snap evidence.WindowSnap
 			c.notify()
 			return
 		}
-		c.judgedClasses[class] = v
+		c.judgedWindows[key] = v
 		var enforceAct func()
-		if c.stats != nil && c.stats.Current.Class == class {
+		if c.stats != nil && verdictKey(c.stats.Current.Class, c.stats.Current.Title) == key {
 			c.applyVerdictLocked(v)
 			enforceAct = c.enforceActionLocked()
 		}
@@ -314,6 +318,15 @@ func (c *Controller) recordTitleLocked(title string) {
 	}
 }
 
+// verdictKey identifies the judged window for the per-window verdict cache. It
+// combines the window class with the scrubbed, casefolded title so sibling
+// windows of one app (a browser's reading tab vs its chat tab) are judged
+// independently, while transient title noise (clocks, counts) does not split a
+// window into ever-changing keys that defeat the cache.
+func verdictKey(class, title string) string {
+	return strings.ToLower(strings.TrimSpace(class)) + "\x00" + strings.ToLower(evidence.ScrubTitle(title))
+}
+
 // applyVerdictLocked maps a verdict onto drift state. Caller holds mu.
 func (c *Controller) applyVerdictLocked(v ai.Verdict) {
 	if v.OnTask {