Activate apps and recover exact windows

[iamnbutler]

Agents can now explicitly activate a running app, focus an exact window, and restore a minimized window with desktop_activate, desktop_focus, and desktop_restore. Targets retain the process generation and observed window bounds. The client verifies signed inventory before dispatch and signed target/outcome receipts afterward. Inspection stays passive; later observation failures preserve completed actions and their original diagnostics.

Implements the focused recovery tools in #73, part of #8. Based on feat/github-cache with merged inspection diagnostics (#71) and click variants (#82), independently of literal insertion (#67).

Final head 5c0dfb16283cd6382a2146ded36f3f6f17f3848d integrates merged application search (#84). The only conflict combined the management request union with the optional application query. Types, formatting/lint, Ace diff review, and independent integration review passed again; native sources are unchanged from the runtime-validated build below.

Validation on ffb47ccc071cbdd2e974ec1478d0cf3ff33d3c0a:

• Types, formatting/lint, signed development build, strict app/client signatures, and independent source review passed.
• Real AppKit callbacks and Save evidence verified activation, already-active no-op, exact focus, actual minimize/restore, already-restored no-op, hidden-app activation, and stale-generation/bounds refusals. Document text remained unchanged. Recorded repeated focus also matched its exact receipt and verified resulting state; focus does not promise an already-key no-op.
• A real pi/Anthropic run executed activate → restore → focus. Exact tool text/images and outcomes survived reopening the same pi store with unchanged usage and no repeated native calls.

The management-specific delayed-response/target-closure check remains unverified: its temporary wrapper had an invalid executable signature and failed before its start marker. Generic completed-action preservation after a failed follow-up was validated in #71. Management-specific Stop/crash recovery and hosted forwarding have not been rerun for this slice.

Built in Ace

Git/GitHub work, builds, checks, diff review, and native/model validation runs used Ace's terminal and channel APIs. Codex provided source editing, coordination, and candidate/fixture launch because Ace's external-harness integration (#9) and file editor (#22) are not yet available. Actual AppKit callbacks, Save files, signed native results, and real pi/provider history supplied the validation evidence.