chore(android): de-anchor ANDROID_PLAN.md from the docs, re-enable the APK workflow

Reword every code comment and doc that referenced ANDROID_PLAN.md or its stage anchors (§E, G-step-0, O1) so the living docs no longer depend on the plan file: .claude/CLAUDE.md, deploy/README.md, docs/ARCHITECTURE.md, docs/TESTING.md, ui/README.md, ui/android/.gitignore, ui/e2e/native.spec.ts, ui/src/lib/netstate.ts.

Re-enable the manual signed-APK workflow (android-build.yaml.disabled -> android-build.yaml; the CI host already has the Android SDK; workflow_dispatch-only, so it does not auto-run on this PR). Add docs/ICONS.md — the single-master icon/logo format reference (web, PWA, Android, future iOS, store listings).

ui/e2e/native.spec.ts

@@ -67,14 +67,14 @@ test.describe('native offline-first', () => {
     // returns: reconciliation silently mints + adopts a server guest and clears the auto-offline, so
     // online lights up — the offline tint drops, the seeded online game (vs Ann) appears and Stats
     // re-enables. The local game STAYS visible in the unified lobby alongside the server games — a
-    // reconciled guest keeps its device-local games (this closes G-step-0).
+    // reconciled guest keeps its device-local games.
     await page.getByRole('button', { name: /Back|Назад/i }).click();
     await expect(page.locator('button.tab').nth(2)).toBeVisible();
     await expect(page.locator('.rowwrap').filter({ hasText: '🤖' })).toBeVisible(); // the local vs_ai game, listed while offline
     await page.evaluate(() => (window as unknown as { __native: { reconcile(): void } }).__native.reconcile());
     await expect(page.locator('header.nav.offline')).toHaveCount(0);
     await expect(page.getByText('Ann', { exact: false }).first()).toBeVisible({ timeout: 15000 });
-    await expect(page.locator('.rowwrap').filter({ hasText: '🤖' })).toBeVisible(); // still listed online — the reconciled guest keeps it (G-step-0)
+    await expect(page.locator('.rowwrap').filter({ hasText: '🤖' })).toBeVisible(); // still listed online — the reconciled guest keeps it
     await expect(page.locator('button.tab').nth(1)).toBeEnabled();
 
     // The native sign-in surface is guest + email only: on Profile the Telegram + VK LINK buttons are