feat: add uncommitted scope to All Changes diff

[liyown]

Related issue

Closes #1664

Problem / pressure

The workspace All Changes diff compared merge-base(base, HEAD) with disk, so
work that had already been committed on the branch stayed in the diff after a
commit. The UI never named the base, so users could not tell branch-cumulative
changes from edits that were still uncommitted. Deferred files also re-resolved
the base independently, which made a scoped view impossible to keep consistent.

Summary

• Add an optional branch | uncommitted scope to the batched All Changes diff
  and to the per-file open-current-diff request.
• uncommitted compares HEAD with disk, including staged, unstaged and
  untracked non-ignored files.
• Non-Git worktrees and repositories without a commit return explicit
  not_a_git_worktree / no_commits reasons instead of silently falling back
  to an untracked-only list.
• Uncommitted mode never falls back to session diff-store snapshots.
• Show a scope control and the resolved base in the All Changes header. The
  control is gated by the codeCollabAllChangesScope protocol capability.
• The Changes sidebar list stays branch-cumulative; the diff view renders only
  the file set returned by the selected scope.

Visual explanation

flowchart LR
  UI["All Changes header<br/>scope: branch | uncommitted"] --> HOOK[useSessionAllChangesDiffData]
  HOOK -->|"batch + scope"| PROVIDER[CodeCollabSessionFileProvider]
  PROVIDER --> RPC[loro-streams-rpc]
  RPC --> SERVICE[CodeCollabV2Service]
  SERVICE -->|branch| MB["merge-base(base, HEAD) -> disk + untracked"]
  SERVICE -->|uncommitted| HEAD["HEAD -> disk: staged + unstaged + untracked"]
  SERVICE -->|"no Git / no HEAD"| ERR[explicit unavailable]
  HOOK -->|"deferred + scope"| DEFER[useSessionConversationDiffData]
  DEFER -->|"open-current-diff + scope"| SERVICE

Loading

Before / after

Before	After
The All Changes base was never named.	The header shows the scope and the resolved base (HEAD · abcdef1, Branch base · 1234567, or Session changes).
Committed branch work remained in the only diff view.	A second scope shows only uncommitted changes; committing clears that view.
A repository without HEAD silently listed only untracked files.	It reports an explicit no_commits state.
Deferred per-file reads always used the branch base.	Deferred reads carry the same scope and never mix bases.

Test plan

• pnpm --dir apps/cli exec vitest run — 4392 passed, 4 skipped on the merged base.
• pnpm --dir packages/components exec vitest run tests/code-collab-session-file-provider-v2.test.ts tests/session-conversation-diff-panel.test.tsx tests/use-session-conversation-diff-data.test.tsx — 41 passed.
• pnpm --filter @lody/components typecheck, pnpm --filter @lody/shared typecheck, pnpm --filter @lody/loro-streams-rpc typecheck — passed.
• pnpm --filter lody typecheck fails on origin/main (796f42c) in apps/cli/src/lib/loro/doc.ts because the pinned loro-repo@0.23.2 type has no runLegacy / acquireScopeLegacy. The same failure reproduces on a clean origin/main checkout and is unrelated to this change.
• pnpm lint:i18n, oxlint, oxfmt --check, pnpm run docs check, pnpm check:code-collab-imports, pnpm check:platform-boundaries — passed.
• Storybook: toggled AllChangesScopeSwitch in a browser; the base label changed to HEAD · abcdef1 and the file set shrank to the uncommitted entries.
• The full components suite still has one unrelated pre-existing failure in tests/boot-shell.test.tsx, reproduced on clean origin/main with the changes stashed.

Context handoff

Original user prompt

Show original prompt

https://github.com/LodyAI/Lody/issues/1664

Shared conversation

Status: unavailable
Reason: Claude desktop app (Code tab) — the author reports that surface cannot publish a public conversation link.