Put the formatter and the linter in the routine that people actually run

AGENTS.md's "Checking your work" listed a typecheck for the app and tests
plus clippy for the server. Neither half mentioned a formatter, and nothing
mentioned Android Lint at all -- which is how a linter that was in the
build the whole time went unrun long enough to accumulate a crash.

Both lines now say the whole thing, and the app's reads as the counterpart
of the server's rather than a shorter version of it. The note about lint is
there because it is the one step a build does not do for you: nothing fails
if you skip it, which is exactly why it needs writing down.

The command in the app bullet is the one I ran to verify this commit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw

AGENTS.md

@@ -64,12 +64,20 @@ real-phone/WireGuard bring-up, which is operational rather than code.
 
 ## Checking your work
 
-- Server: `./run-tests.sh` (or `cargo test`) + `cargo clippy --all-targets`
-  from `server/` — the build stays warning-clean, keep it that way.
-- App: from `app/`, `. ./android-env.sh && ./gradlew :androidApp:compileDebugKotlin`
-  to typecheck; `./build-apk.sh` to produce the APK to install on a phone
-  (through Dev Updater); `./run-android.sh` to build, install, and launch
-  on the emulator.
+- Server: from `server/`, `./run-tests.sh` (or `cargo test`) +
+  `cargo clippy --all-targets` + `cargo fmt`. The build stays
+  warning-clean and rustfmt-clean at the defaults — there is no
+  `rustfmt.toml` and there should not be one.
+- App: from `app/`, `. ./android-env.sh && ./gradlew :androidApp:ktfmtFormat
+  :androidApp:compileDebugKotlin :androidApp:lintDebug` — format, typecheck
+  and lint, the app-side equivalent of the line above. Then `./build-apk.sh`
+  to produce the APK to install on a phone (through Dev Updater), or
+  `./run-android.sh` to build, install, and launch on the emulator.
+- **Android Lint is not optional and is not run by a build.** It found a
+  crash that had been shipping: `java.time` on a minSdk-24 app with
+  desugaring off. It is clean now apart from Compose 1.11.1 having a 1.12.0
+  available; keep it that way, and suppress with `tools:ignore` plus a
+  written reason rather than by lowering the bar.
 - **The APK pins the CA of the machine that builds it**, read at build time
   from `$XDG_CONFIG_HOME/ai-app/certs/ca.pem` (`AI_APP_CA` overrides) and
   generated into a constant. So the server must have started once on that