refactor(typeaware): no-unnecessary-type-conversion + unbound-method sweep (T3.b partial) (#754)

* refactor: clear no-unnecessary-type-conversion + unbound-method (T3.b partial)

Fixes 15 files within the hard cap:

unbound-method (interface method shorthand → property function syntax):
- pane-context.tsx: PaneContextValue + PaneFocusContextValue (fixes agent-panel, browser-panel, draft-panel)
- provider-runner.ts: ProviderTurnRunner interface
- process-tree.ts: process.kill.bind(process)

no-unnecessary-type-conversion (remove redundant Boolean()/String() wraps):
- agent-timeline-store.ts, worktree-session.ts, pairing-qr.ts
- sherpa-realtime-session.ts, sherpa-stt.ts (String() → direct call chain)
- workspace-execution.ts, confirm-dialog.ts, use-archive-agent.ts
- use-agent-history.ts, left-sidebar.tsx, autocomplete.tsx, dropdown-menu.tsx

Deferred (9 errors across 7 files, all single-line Boolean(hovered) removals):
project-picker-modal.tsx, agent-list.tsx, branch-switcher.tsx,
file-explorer-pane.tsx, workspace-open-in-editor-button.tsx,
browser-pane.electron.tsx, sortable-inline-list.web.tsx

* fix(app): preserve Boolean coercion fallback in archive state lookups

readPendingState(...)[key] and (pendingQuery.data ?? {})[key] return
boolean | undefined at runtime — noUncheckedIndexedAccess is off so
TypeScript types this as boolean but the actual value can be undefined.
Add ?? false to maintain the explicit boolean return contract.

packages/server/src/utils/process-tree.ts

@@ -75,7 +75,7 @@ export function signalProcessTree(
     }
 
     try {
-      (options.kill ?? process.kill)(-pid, signal);
+      (options.kill ?? process.kill.bind(process))(-pid, signal);
       return;
     } catch {
       // Fall back to the direct child when no separate process group exists.