Validate native VS Code window continuity and terminal readout

docs/terminal-compatibility.md

@@ -41,11 +41,11 @@ First-run dialogs are handled before fixture input. The offline fixture denies o
 
 VS Code uses separate disposable profiles for idle and streaming cases under a short `/private/tmp/ah-vsc-*` directory. Its [main IPC socket](https://github.com/microsoft/vscode/blob/main/src/vs/base/parts/ipc/node/ipc.net.ts) lives under the user-data directory, so putting profiles below a long checkout path can exceed macOS's Unix socket limit and make Code exit before creating a window. Settings evidence stays under the checkout's `.artifacts/native-terminal/` directory, and bounded main-log tails are attached to XCTest results. The profiles enable [`chat.disableAIFeatures`](https://code.visualstudio.com/docs/agents/reference/ai-settings) to suppress built-in Copilot onboarding. VS Code also launches with [`--force-renderer-accessibility`](https://www.chromium.org/developers/design-documents/accessibility/) to expose Chromium's native accessibility tree; the editor's screen-reader setting alone does not ensure that tree is available to XCTest. The scenario opens the terminal through its native Terminal > New Terminal menu. If the specific Copilot sign-in dialog still appears, the scenario closes that dialog and opens the integrated terminal. It does not sign in or grant network access. Window, workbench, and terminal-view failures preserve bounded accessibility diagnostics and screenshots; the workflow also retains the Xcode output and generated VS Code settings.
 
-Native scenarios first size and position their fixture window within the reported display's visible bounds, leaving room for all four physical resize gestures. Setup shrinks oversized dimensions before moving the window, then grows it at the target position, so a full-width window's resize handle never moves off-screen. VS Code's input readiness uses the native Split Terminal command becoming enabled after New Terminal, which establishes terminal focus; it does not require xterm's input to expose the same TextView role as standalone terminals. The fixture's rendered output remains the mandatory proof that paste, Enter, and terminal rendering worked. All scenarios retain the exact transcript, streaming, draft, cursor, resize, and exit assertions.
+Native scenarios first size and position their fixture window within the reported display's visible bounds, leaving room for all four physical resize gestures. Setup shrinks oversized dimensions before moving the window, then grows it at the target position, so a full-width window's resize handle never moves off-screen. VS Code setup starts after terminal readiness and verifies the actual width and height accepted by each gesture; a partially accepted shrink cannot authorize an off-screen move. VS Code's input readiness uses the native Split Terminal command becoming enabled after New Terminal, which establishes terminal focus; it does not require xterm's input to expose the same TextView role as standalone terminals. The fixture's rendered output remains the mandatory proof that paste, Enter, and terminal rendering worked. All scenarios retain the exact transcript, streaming, draft, cursor, resize, and exit assertions.
 
-VS Code's readout preflight captures one immutable native window snapshot and searches at most 2,048 nodes for a TextView buffer containing the real fixture-history marker. It does not concatenate workbench StaticText nodes: xterm exposes both individual screen rows and a live announcement region, which can repeat hundreds of full-screen redraw announcements. Those announcements are not the terminal buffer. The native snapshot avoids separate remote accessibility calls for every node and attribute; exceeding its traversal budget fails closed to the buffer-copy preflight. If accessibility lacks it, a disposable-profile shortcut uses [`runCommands`](https://code.visualstudio.com/docs/configure/keybindings#_running-multiple-commands) to select the full terminal buffer and [copy and clear its selection](https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/terminalContrib/clipboard/browser/terminal.clipboard.contribution.ts). The preflight uses that raw copied buffer only if it contains the actual fixture marker and a second accessibility read still lacks it. Each subsequent copy clears the pasteboard and requires a new pasteboard generation; old frames cannot satisfy later resize checks. A temporarily unavailable copy produces no frame; the original startup, resize, cursor, or exit predicate retains its deadline. Once resize readiness accepts a fresh raw frame, all exact counts and streaming assertions inspect that same frame without issuing a second copy. Readiness checks only history and draft presence, so duplicated accepted frames still fail immediately. The command clears terminal selection while preserving focus and the PTY cursor, which the existing cursor-edit assertion verifies. No terminal output is filtered or deduplicated. Readout samples, selected backend, settings, and keybindings are retained with native results.
+VS Code's readout preflight captures one immutable app snapshot, scopes it to the fixture's current native window frame, and searches at most 2,048 nodes. Its native process ID, Core Graphics window ID, and single-window count remain fixed through all gestures and reads, while accessibility window references are refreshed after resize. [xterm's accessibility tree](https://github.com/xtermjs/xterm.js/blob/master/src/browser/AccessibilityManager.ts) exposes a screen-row list separately from its live announcement region. In the recorded macOS tree this is an Other node containing consecutive, equal-height Group rows, each with one StaticText value. The adapter requires one unambiguous, complete row list in the native window; it preserves row order, blank rows, and repeated values. xterm scales each accessibility row to its text and cell width, so rows can be wider than the list container after resize; the adapter validates their vertical grid without requiring horizontal containment. It never selects rows based on fixture content or concatenates announcement siblings. Native TextView buffers remain supported. Ambiguous, oversized, malformed, or stale snapshots fail closed to the buffer-copy preflight. If accessibility lacks it, a disposable-profile shortcut uses [`runCommands`](https://code.visualstudio.com/docs/configure/keybindings#_running-multiple-commands) to select the full terminal buffer and [copy and clear its selection](https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/terminalContrib/clipboard/browser/terminal.clipboard.contribution.ts). The preflight uses that raw copied buffer only if it contains the actual fixture marker and a second accessibility read still lacks it. Each subsequent copy clears the pasteboard and requires a new pasteboard generation; old frames cannot satisfy later resize checks. A temporarily unavailable copy produces no frame; the original startup, resize, cursor, or exit predicate retains its deadline. Once resize readiness accepts a fresh raw frame, all exact counts and streaming assertions inspect that same frame without issuing a second copy. Resize readiness requires the header, history, draft, and the stream marker for streaming scenarios, without examining their counts. This avoids accepting a partial accessibility update before the header returns; duplicated accepted frames still fail immediately against the exact-count assertions. Permanent marker loss fails the original settling deadline. The command clears terminal selection while preserving focus and the PTY cursor, which the existing cursor-edit assertion verifies. No terminal output is filtered or deduplicated. Readout samples, selected backend, settings, and keybindings are retained with native results.
 
-The strict visible-history assertions require room for both transcript exchanges and the multiline composer. At a compact 57×19 terminal, the full-screen transcript correctly follows its newest exchange and clips older rows; a separate PTY case checks that the history reappears on growth, the draft and cursor survive, and Ctrl+C exits cleanly. This distinguishes viewport clipping from lost transcript data. Native window references bind to their accessibility identities so later queries continue inspecting the resized window.
+The strict visible-history assertions require room for both transcript exchanges and the multiline composer. At a compact 57×19 terminal, the full-screen transcript correctly follows its newest exchange and clips older rows; a separate PTY case checks that the history reappears on growth, the draft and cursor survive, and Ctrl+C exits cleanly. This distinguishes viewport clipping from lost transcript data. Standalone terminal references bind to their accessibility identities. VS Code refreshes its accessibility window before setup steps and after every setup or scenario gesture, guarded by the same native process ID, window ID, single-window count, and current frame.
 
 Native CI availability and per-application results must be assessed from that workflow's completed jobs. A passing PTY suite or a successful XCTest build alone does not prove a native application passed. Failures in app launch, accessibility access, or window resizing fail the native job and preserve its XCTest evidence; they are not silently converted to headless passes.