feat(desktop): replicate Codex computer-use cursor

[hqhq1025]

Summary

• replace the active desktop cursor renderer with the recovered Codex Fog cursor geometry and center-hotspot convention
• use a 20-candidate cubic path planner with distance-adaptive spring progress and long-move scoot rotation/stretch
• preserve the latest overlay completion, cancellation, presentation-fence, and legacy Dubins APIs
• document the inspected native artifact, exact AgentCursor path, and MotionConfiguration constants

Reverse-engineering boundary

The glyph path, center hotspot, thresholds, and all recovered motion constants come from the signed 2026-07-16 SkyComputerUseService binary. The native candidate scoring function is stripped, so the planner is a structural reproduction using the exact recovered handle and arc constants; it is not presented as instruction-for-instruction equivalence.

Base CI repair

The latest main branch failed the repository-wide format check in packages/storage/src/__tests__/settings-store-usage.test.ts. A separate mechanical style(storage) commit applies Biome's formatting only, with no semantic changes, so this PR can run against a clean baseline.

Visual validation

Validation

• serial builds: core, storage, runtime, computer-use, ui, mcp, runtime-host
• desktop main build
• desktop overlay bundle build
• cursor engine, overlay window, and cursor convention tests: 29 passed
• repository-wide Biome lint and format check

[hqhq1025]

CI follow-up: the failure was the latest main branch's repository-wide format baseline in packages/storage/src/__tests__/settings-store-usage.test.ts. This PR now includes a separate mechanical style(storage) commit containing only Biome's two object-literal line wraps. Repository-wide lint and format checks pass locally; cursor main/overlay builds and the 29 related tests also pass.

[Astro-Han]

Two P2 comments on cursor edge behavior. Neither rises to P1, so I am approving with comments.

[hqhq1025]

@Astro-Han Both P2 comments are addressed in 5395fb2: viewport-aware path scoring/direct fallback plus cancel-opacity reset, with regressions for the reported edge path and cancel-during-fade. The refreshed typecheck, test, and e2e checks are all green. Re-review when convenient.

[Astro-Han]

LGTM now! Merging.