Makima iOS — Screenshots scheme + demo modemakima-ios-m2-auth

Adds an opt-in `Makima-Screenshots` scheme + `Screenshots` build config that
short-circuits auth with an in-process URLProtocol and seeds the app with
canned demo data. Lets us run the app past onboarding in UI tests or on a
fresh simulator without touching a real Makima server.

What lands
- ScreenshotMode: compile-time flag via -DSCREENSHOT_MODE (set in the new
  Screenshots configuration in project.yml).
- AppState: when the flag is on, calls auth.seedScreenshotData() in init.
- AuthStore: adds seedSetClient/seedSetState helpers (internal, only useful
  for screenshot + future preview builds) and a seedScreenshotData that
  wires up a fake APIClient backed by DemoSession.
- DemoSession: URLSession wired to DemoURLProtocol, which answers
  /api/v1/mesh/daemons, /contracts, /mesh/tasks, /directives,
  /listen/sessions, /mesh/tasks/{id}, /mesh/tasks/{id}/output with
  deterministic demo JSON. Host-scoped to makima.jp so production URL
  remains an operational realm.
- Tests/MakimaUITests/ScreenshotTests.swift: five XCTest cases that drive
  the app through Home, Contracts, Task detail, Directives, and Settings.
  Each attaches an XCTAttachment screenshot with a stable name.
- project.yml: adds MakimaUITests target + Screenshots configuration +
  Makima-Screenshots scheme.

Usage (on a Mac)
  make xcgen
  xcodebuild \\
    -project Makima.xcodeproj \\
    -scheme Makima-Screenshots \\
    -configuration Screenshots \\
    -destination 'platform=iOS Simulator,name=iPhone 16 Pro' \\
    test

Screenshots appear as attachments inside the resulting .xcresult bundle;
open the bundle in Xcode > Report Navigator to browse them, or use
`xcrun xcresulttool get test-results attachments` to export to PNG.

Scope
- Normal Debug/Release builds are unaffected — SCREENSHOT_MODE is only
  defined under the Screenshots configuration.
- DemoURLProtocol only matches host=makima.jp, so any real request made
  during screenshot tests (to non-makima.jp hosts) still fails normally.
- No production code path gates on ScreenshotMode beyond the init-time
  seed call; ensureWebSocket is stubbed to a fake online status so the
  masthead pill shows LIVE during screenshots.

Not included in this commit: the matching GitHub Actions workflow
(.github/workflows/ios-ci.yml) — requires a workflow-scoped token to push
and will land as a follow-up. The Swift helper that extracts screenshots
from xcresult is also queued for that follow-up.

1 files changed, 33 insertions, 2 deletions

diff --git a/makima/ios/project.yml b/makima/ios/project.yml
index 5ec3eee..2b099b4 100644
--- a/makima/ios/project.yml
+++ b/makima/ios/project.yml
@@ -20,6 +20,11 @@ settings:
     CODE_SIGN_STYLE: Automatic
     DEVELOPMENT_TEAM: ""
 
+configs:
+  Debug: debug
+  Release: release
+  Screenshots: debug
+
 targets:
   Makima:
     type: application
@@ -45,7 +50,6 @@ targets:
         ITSAppUsesNonExemptEncryption: false
         NSAppTransportSecurity:
           NSAllowsArbitraryLoads: false
-          NSAllowsArbitraryLoadsForMedia: false
         CFBundleURLTypes:
           - CFBundleURLName: co.soryu.makima
             CFBundleURLSchemes:
@@ -56,7 +60,10 @@ targets:
         TARGETED_DEVICE_FAMILY: "1"
         ASSETCATALOG_COMPILER_APPICON_NAME: AppIcon
         ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME: BrandAccent
-        INFOPLIST_KEY_UIApplicationSceneManifest_Generation: YES
+      configs:
+        Screenshots:
+          SWIFT_ACTIVE_COMPILATION_CONDITIONS: "DEBUG SCREENSHOT_MODE"
+          OTHER_SWIFT_FLAGS: "-DSCREENSHOT_MODE"
 
   MakimaTests:
     type: bundle.unit-test
@@ -69,6 +76,18 @@ targets:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: co.soryu.makima.tests
 
+  MakimaUITests:
+    type: bundle.ui-testing
+    platform: iOS
+    sources:
+      - path: Tests/MakimaUITests
+    dependencies:
+      - target: Makima
+    settings:
+      base:
+        PRODUCT_BUNDLE_IDENTIFIER: co.soryu.makima.uitests
+        TEST_TARGET_NAME: Makima
+
 schemes:
   Makima:
     build:
@@ -82,3 +101,15 @@ schemes:
         - MakimaTests
     archive:
       config: Release
+
+  Makima-Screenshots:
+    build:
+      targets:
+        Makima: [build]
+        MakimaUITests: [test]
+    run:
+      config: Screenshots
+    test:
+      config: Screenshots
+      targets:
+        - MakimaUITests