feat(app): Files Changed flat filename list with tree popover on click

[jeonghun-jj-lee]

Replaces the always-visible FileTree in the 'Files Changed' side panel tab with a compact flat filename list and on-demand tree popover.

Changes

• New pure utilities (file-list-model.ts in opencode app): getCommonAncestor, disambiguateFilenames, sortPathsByFilename — fully unit tested (14 tests)
• New component (FileListFlat): flat alphabetical list with change-kind indicators, tooltip on hover, floating tree popover on click
• Integration: replaces the <FileTree> in the 'changes' sub-tab of session-side-panel.tsx

Behavior

• Filenames are shown alphabetically (basename only)
• Duplicate basenames get minimum parent disambiguation in parentheses
• Hover shows full relative path in a tooltip
• Click opens a floating popover with the full tree rooted at the common ancestor
• Clicked file is highlighted in the tree; selecting any file navigates to its diff

Closes #551

Summary by CodeRabbit

• New Features
  • Added a new session review panel with diff previews, comments, file navigation, search, and keyboard controls.
  • Added tree and list views for browsing changed files, including filtering, resizing, and diff statistics.
  • Added a file picker with hierarchical navigation and selectable file paths.
  • Added loading states and improved file selection handling in session review previews.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 290bc341-e91f-4365-ae99-f0c115fc48c6

📥 Commits

Reviewing files that changed from the base of the PR and between 3bb443f and 98f45fb.

📒 Files selected for processing (4)

• packages/app-bundle/manifest.json
• packages/app-bundle/overlay/packages/app/src/pages/session/v2/review-panel-v2.tsx
• packages/app-bundle/overlay/packages/session-ui/src/v2/components/session-review-file-preview-v2.tsx
• packages/app-bundle/overlay/packages/session-ui/src/v2/components/session-review-v2.css

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📝 Walkthrough

Walkthrough

The PR adds ReviewPanelV2 with diff loading, sidebar navigation, and collapsed file-tree selection. It integrates a file picker into the session review preview, adds picker styling, and updates the app-bundle manifest and file hashes.

Changes

Session review navigation

Layer / File(s)	Summary
Review panel and file navigation packages/app-bundle/overlay/packages/app/src/pages/session/v2/review-panel-v2.tsx	Adds ReviewPanelV2, asynchronous diff and file loading, active-file selection, searchable sidebar navigation, resizing, and collapsed file-tree utilities.
File-picker preview integration packages/app-bundle/overlay/packages/session-ui/src/v2/components/session-review-file-preview-v2.tsx, packages/app-bundle/overlay/packages/session-ui/src/v2/components/session-review-v2.css	Adds optional picker rendering and file-selection callbacks. The preview supports picker dismissal and selection. CSS styles the trigger, dropdown, tree rows, indentation, and active states.
Bundle manifest synchronization packages/app-bundle/manifest.json	Updates the app addition count, classified file inventory, and hashes for changed app and UI files.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Reviewer
  participant ReviewPanelV2
  participant SessionSDK
  participant SessionReviewFilePreviewV2
  Reviewer->>ReviewPanelV2: select a changed file
  ReviewPanelV2->>SessionSDK: load diff and file content
  SessionSDK-->>ReviewPanelV2: return file data
  ReviewPanelV2->>SessionReviewFilePreviewV2: render the active preview
  SessionReviewFilePreviewV2-->>Reviewer: display selected file and diff

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Suggested reviewers: aarontrowbridge

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch 551-files-changed-flat-list-tree-popover

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