Ground-up replacement for the DevPilot APK whose source was lost in the Sep 1
wipe. That app could only be maintained by guessing at an opaque binary: two
days went into inferring its wire contract from `strings` on libapp.so, and the
last bug (every text file rendering as "Binary file") was never solvable from
the server side at all. Owning the source ends that entire class of problem.

Five tabs, each backed by a real endpoint:
  VS Code   code-server in a webview, host derived from the API host
  Chats     multi-turn conversations, live SSE, per-message model and effort,
            attachments from the phone, local notification when a run lands
  Files     project-scoped browser, re_editor with syntax highlighting,
            markdown rendered with mermaid diagrams, create/rename/delete/upload
  Git       per-repo status, coloured diff, pull/commit/push
  Settings  Claude usage against both rolling windows, connection, sign out

Decisions worth recording:

- models.dart parses defensively on purpose. Every fromJson is total and a
  wrong-typed field degrades to a default. The old client did the opposite and
  one bad field made *every* file unopenable, because a throw inside fromJson
  loses the whole object rather than one value.
- Binary is believed only when the server explicitly says so. Treating "unknown"
  as binary is precisely the bug that made the previous app useless.
- SSE is read off a raw HttpClient, not Dio: it is a line protocol held open
  indefinitely and Dio is built around a body that ends. The stream resumes with
  ?from=N so backgrounding the phone does not lose output.
- Mermaid renders in a webview because no Dart package draws it; the source is
  passed as a JSON literal so quotes and newlines cannot break out, and it falls
  back to showing the source offline instead of an empty box.
- Tabs live in an IndexedStack so scroll position, open directory and in-flight
  streams survive switching away — the app exists to leave work running.
- No FCM. The server has nothing to push with, and the only event worth an
  interruption is one the app already observes.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>