feat(app): add workspace flows to new layout

[Hona]

Summary

• Add Local/New/Existing workspace selection for new sessions with persisted, validated drafts and readiness handling.
• Add changed-session move flows, lifecycle rows, neutral workspace headers, and a 280px working-changes details panel.
• Normalize current and V1 moved events with app-side placement, reindexing, concurrency, timeout, and failure guards.
• Use existing APIs only; no Core/API/generated changes.

Scope

• App-only: packages/app/**.
• Excludes workspace settings/inventory/list/delete/reset, automatic cleanup/default destination/View all, arbitrary CWD, and durable operation recovery/readiness replay.

Testing

• Release integration: app bun typecheck passed; bun run typecheck:e2e passed.
• Release integration: 167 focused unit tests passed across isolated Bun processes (61 feature/timeline plus 106 server/event tests).
• Release integration: 15 Playwright tests passed (5 workspace E2Es and 10 timeline projection/lifecycle E2Es).
• Pre-push hook: repository bun turbo typecheck passed for all 30 packages.
• Reviewed signoff: 162 focused tests, 30 browser tests, 5 workspace E2Es, and 10 timeline projection/lifecycle E2Es passed; git diff --check passed.
• Performance: exclusive interleaved target/base/target/base production runs materially overlapped; the two-run target average was +5.8%, one target run was faster than both base runs, context and scrollHeight were identical, and blanks/drift/row replacement/Markdown replacement were all zero.
• The full unit suite has an unrelated upstream locale-parity failure because Arabic lacks five existing non-workspace English keys; this PR does not add or modify those keys.

Risk

• Existing worktree.ready is non-replayable; timeout/failure remains the inherited fallback.

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