build: lib/ pipeline via react-native-builder-bob (closes #47)

.github/workflows/ci.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
   push:
     branches: [develop]
+  # Toolchain drift (`xcode-version: latest-stable`) can fail a run that a
+  # later Xcode builds cleanly, and GitHub refuses to retry runs older than a
+  # month — so allow a manual re-run without a no-op commit.
+  workflow_dispatch:
 
 jobs:
   typecheck:
@@ -127,7 +131,10 @@ jobs:
 
   build-macos:
     name: Build (macOS, bare RN-macos)
-    runs-on: macos-15
+    # macos-15 caps at Xcode 26.3, whose toolchain cannot resolve the Swift
+    # back-deployment shims (`libswiftCompatibility56`) that the vendored SPM
+    # deps force-load — the same commit links clean under Xcode 26.6 locally.
+    runs-on: macos-26
     needs: typecheck
     steps:
       - uses: actions/checkout@v4
@@ -170,4 +177,5 @@ jobs:
             -configuration Debug \
             -destination 'platform=macOS' \
             CODE_SIGNING_ALLOWED=NO \
+            MACOSX_DEPLOYMENT_TARGET=14.0 \
             build

.gitignore

@@ -62,3 +62,6 @@ yarn-error.log
 
 # Claude Code per-user settings
 .claude/settings.local.json
+
+# Generated build output (bob)
+lib/