test(07-01): FS1-FS9 fullscreen gates + mock satisfies the grown contract

- telegram-mock gains requestFullscreen/exitFullscreen/lockOrientation/unlockOrientation + __fullscreen* state fields in the SAME change as the contract (contract + fake + test together)
- FS1-FS7: both-halves guard vectors, the throwing-platform path (FS4), the exit mirror (FS5), the event categories (FS6), the old-client fallback (FS7, SC2.e)
- FS8: safeAreaChanged re-resolution through the union authority, with a minimal document stub restored in finally
- FS9: comment-stripped source-scan ban on the DOM-fullscreen/orientation-lock escape hatches (T-07-10) + the guard-is-not-optional assertion
- suite 157 passed, 0 failed (148 baseline + 9); mutation check: neutering the 8.0 guard fails FS2/FS5

web/src/mock/telegram-mock.ts

@@ -93,6 +93,11 @@ interface MockWebApp extends TelegramWebAppLike {
   __events: Map<string, Array<() => void>>;
   __backButtonClicks: Array<() => void>;
   __homeScreenAdded: number;
+  __fullscreenRequested: number;
+  __fullscreenExited: number;
+  __orientationLocked: number;
+  __orientationUnlocked: number;
+  __isFullscreen: boolean;
 }
 
 /* ————— Web-Crypto dev signer (mirror of bot/src/security/initdata.ts's HMAC path) ————— */
@@ -415,6 +420,11 @@ export function installMockWebApp(options: MockOptions = {}): TelegramWebAppLike
     __events: events,
     __backButtonClicks: backButtonClicks,
     __homeScreenAdded: 0,
+    __fullscreenRequested: 0,
+    __fullscreenExited: 0,
+    __orientationLocked: 0,
+    __orientationUnlocked: 0,
+    __isFullscreen: false,
     isVersionAtLeast(v: string) {
       return versionAtLeast(version, v);
     },
@@ -428,6 +438,25 @@ export function installMockWebApp(options: MockOptions = {}): TelegramWebAppLike
     checkHomeScreenStatus(cb: (status: HomeScreenStatus) => void) {
       setTimeout(() => cb(homeScreenStatus), 0);
     },
+    // PX-04/D-03 (07-01): the fullscreen members ship with the contract —
+    // the mock satisfies the grown contract in the SAME change ("contract +
+    // fake + test together"). The ?mock= profile's `version` below 8.0 makes
+    // the fullscreen path a silent no-op via the version guard — never
+    // hard-coded, the mock's own versionAtLeast drives the guard.
+    requestFullscreen() {
+      fake.__fullscreenRequested = (fake.__fullscreenRequested ?? 0) + 1;
+      fake.__isFullscreen = true;
+    },
+    exitFullscreen() {
+      fake.__fullscreenExited = (fake.__fullscreenExited ?? 0) + 1;
+      fake.__isFullscreen = false;
+    },
+    lockOrientation() {
+      fake.__orientationLocked = (fake.__orientationLocked ?? 0) + 1;
+    },
+    unlockOrientation() {
+      fake.__orientationUnlocked = (fake.__orientationUnlocked ?? 0) + 1;
+    },
     onEvent(event: string, cb: () => void) {
       const list = events.get(event) ?? [];
       list.push(cb);