feat(android): Projects/Diff/Worktree/git-write parity with web+iOS (W5)

Brings the native Android client to parity with the web/iOS Projects + git surface,
consuming the existing server endpoints — ZERO server change. (The "SDK-gated modules"
premise was stale; they were already online.)

- :api-client (pure Kotlin/JVM): PrStatus/GitLog/GitWrite models (tolerant decoders,
  safe-error), ProjectInfo + ahead/behind/lastCommitMs; 8 new Endpoints builders
  (projectPr/projectLog read-only; createWorktree/removeWorktree/prune/gitStage/
  gitCommit/gitPush guarded w/ Origin) + ApiClient methods (PR/log degrade in body;
  writes 200→Ok / 429→RateLimited / 4xx-5xx→Rejected(safe msg)).
- :app presenters (JVM-tested): DiffViewModel base-compare + git stage/commit/push;
  new WorktreeViewModel (create/remove/prune + client branch validation + isMain block);
  ProjectDetailViewModel failure-isolated PR-chip + recent-commits.
- Compose screens wired: ProjectDetail (PR chip tappable only for https, recent commits,
  worktree create/remove-with-force/prune, view-diff), Diff (base input, per-file
  stage/unstage, commit/push bar), Projects (ahead/behind sync chip). Nav closes the
  pre-existing "no inbound link to the diff screen" gap.

Verified independently: `./gradlew :app:assembleDebug test :api-client:koverVerify`
BUILD SUCCESSFUL; 348 unit tests pass (api-client 102 / app 246); coverage gate held;
git status android-only. Compose rendering/interaction deferred to on-device QA
(android/DEVICE_QA_CHECKLIST.md), as prior Android waves did.

android/README.md

@@ -9,22 +9,20 @@ This directory is a **Gradle multi-module** project. The module set mirrors the
 SPM package set and inherits its rule: *dependencies only flow down; nothing points
 upward* (ARCHITECTURE §1).
 
-## ⚠️ No-SDK constraint (why only 5 modules build here)
+## Build environment (SDK installed — all modules build)
 
-The current build environment has **no Android SDK**. Everything that can be pure
-**Kotlin/JVM** (`kotlin("jvm")`) is built and unit-tested now; anything that needs the
-Android framework (`com.android.*` plugins) is **scaffolded but disabled**.
+The Android SDK **is installed** and every module — pure Kotlin/JVM and Android-framework
+alike — builds and unit-tests here. AGP 9.2.1 (built-in Kotlin) + Gradle 9.6.1 build
+against SDK 35/36.
 
-- **Enabled now (pure Kotlin/JVM, `./gradlew test`-able):**
-  `:wire-protocol`, `:session-core`, `:api-client`, `:client-tls`, `:test-support`.
-- **Scaffolded but COMMENTED OUT** in [`settings.gradle.kts`](settings.gradle.kts)
-  (dirs + a `build.gradle.kts` stub exist, marked `// TODO(android-sdk)`):
+- **Pure Kotlin/JVM (`./gradlew test`):** `:wire-protocol`, `:session-core`, `:api-client`,
+  `:client-tls`, `:test-support`, `:transport-okhttp`.
+- **Android-framework (online in [`settings.gradle.kts`](settings.gradle.kts)):**
   `:app`, `:terminal-view`, `:host-registry`, `:client-tls-android`.
 
-To bring the Android modules online later: install an SDK, add
-`local.properties` → `sdk.dir`, add the Android Gradle Plugin + `google()` to
-`pluginManagement`, then uncomment the `include(...)` lines and the plugin blocks in
-each stub.
+Setup: `local.properties` → `sdk.dir=/usr/local/share/android-commandlinetools`;
+`google()` is in `pluginManagement`/`dependencyResolutionManagement`. Green gate:
+`./gradlew test :app:assembleDebug koverVerify`.
 
 ## Module map (mirror of the iOS SPM packages — plan §3)
 
@@ -35,10 +33,10 @@ each stub.
 | APIClient              | `:api-client`          | pure Kotlin/JVM               | ✅ built |
 | ClientTLS (pure half)  | `:client-tls`          | pure Kotlin/JVM               | ✅ built |
 | TestSupport            | `:test-support`        | pure Kotlin/JVM (fakes)       | ✅ built |
-| ClientTLS (fwk half)   | `:client-tls-android`  | Android (AndroidKeyStore/Tink)| ⏸ SDK-gated |
-| HostRegistry           | `:host-registry`       | Android (DataStore)           | ⏸ SDK-gated |
-| SwiftTerm host view    | `:terminal-view`       | Android (Termux wrap)         | ⏸ SDK-gated |
-| App/WebTerm            | `:app`                 | Android app (Compose/Hilt/FCM)| ⏸ SDK-gated |
+| ClientTLS (fwk half)   | `:client-tls-android`  | Android (AndroidKeyStore/Tink)| ✅ built |
+| HostRegistry           | `:host-registry`       | Android (DataStore)           | ✅ built |
+| SwiftTerm host view    | `:terminal-view`       | Android (Termux wrap)         | ✅ built |
+| App/WebTerm            | `:app`                 | Android app (Compose/Hilt/FCM)| ✅ built |
 
 > Not yet scaffolded: `:transport-okhttp` (OkHttp `TermTransport`/`HttpTransport`
 > impls, JVM) is owned by task **A7** and will be added then. The iOS
@@ -47,16 +45,16 @@ each stub.
 ### Dependency graph (arrows = "depends on")
 
 ```
-                          :app  (SDK-gated)
+                          :app
         ┌───────────────┬───┴────┬──────────────┬───────────────┐
         ▼               ▼        ▼              ▼               ▼
  :terminal-view   :session-core :api-client  :host-registry  :client-tls-android
-   (SDK-gated)         │          │           (SDK-gated)         │
+        │              │          │                               │
         │              │          │                               ▼
         │              │          │                          :client-tls (pure)
         └──────┬───────┴──────────┴──────────────┬────────────────┘
                ▼                                  ▼
-         :wire-protocol   ◀────────────  :transport-okhttp (A7, not yet)
+         :wire-protocol   ◀────────────  :transport-okhttp
                ▲
                └──────── :test-support  → test source sets only
 ```