[codex] Add workspace camera animation mode

[HendrikD2005]

Summary

Adds configurable workspace camera animation for Issue #1623. Minimal preserves the current immediate pan/zoom behavior, while Smooth eases the workspace camera toward scroll and zoom targets. The change extends the existing useWorkspace camera path and Settings appearance preferences.

Refs #1623

Scope

• In scope: browser-local Minimal / Smooth preference, Settings wiring, requestAnimationFrame interpolation, reduced-motion fallback, focused tests.
• Out of scope: new canvas/graph substrate, server persistence, BFF routes, layout/registry/connection redesign.

Reuse And No-Duplication

• Existing Keiko functionality was inspected before implementation.
• Reuses the existing useWorkspace camera owner and browser-local workspace appearance preference pattern.
• New code is limited to the documented visual-interpolation gap in Add configurable workspace camera animation mode #1623.
• Does not introduce a parallel workspace, camera, renderer, graph, or persistence subsystem.

Delivery Board

• Issue label reflects active work: status: in progress.
• Autonomous agents did not merge, enable auto-merge, close the issue, or bypass human review.
• Required project board fields and human review metadata remain maintainer/project-owner follow-up.

Note: #1623 is intentionally a standalone Feature / Task without a parent epic per maintainer instruction.

Product Impact

• UI or user workflow
• CLI or developer workflow
• Core generation engine
• Evidence, audit, or compliance artifact
• Security or supply chain
• Packaging, release, or npm publication
• Documentation or repository hygiene
• No user-facing behavior change

Verification

Local verification:

npm.cmd --workspace @oscharko-dev/keiko-ui run test -- useWorkspace.wheel.test.tsx
PASS: 1 file, 6 tests

npm.cmd --workspace @oscharko-dev/keiko-ui run test -- SettingsPanel.test.tsx
PASS: 1 file, 29 tests

npm.cmd run typecheck
PASS

npm.cmd run lint
PASS

Additional suite notes:

npm.cmd test
FAIL: repository-wide suite is currently red on this Windows environment in unrelated filesystem/symlink/POSIX-mode and unrelated package tests.

npm.cmd --workspace @oscharko-dev/keiko-ui run test
FAIL: 222/223 files passed; failures are isolated to existing src/app/globals.css.test.ts CSS string/snapshot expectations, not touched workspace/settings files.

Reuse / gap rationale:

ADR-0026 keeps useWorkspace as the canonical workspace editor and View { zoom, x, y } as the camera record. This PR extends that hook instead of creating a parallel camera owner or canvas renderer. The gap is visual interpolation: existing wheel handling coalesced view updates with rAF but still committed the visible view directly.

Review And Closure

• The PR implements only the linked issue scope.
• Required GitHub checks pass before merge.
• Actionable review findings are fixed or explicitly dispositioned.
• Checks are repeated after the latest pushed fix.

Risk Notes

• Smooth mode changes visible camera timing, not canonical target coordinates or zoom clamps.
• Reduced-motion users receive immediate updates even when Smooth is selected.
• Preference is browser-local and does not migrate or modify server-owned workspace state.

[oscharko]

Commits must have verified signatures.

[HendrikD2005]

No longer needed. See: #1625