A new shot_review tool, and a multitude of PNG/SVG screenshotter fixes.

.github/actions/run-gates/action.yml

@@ -133,6 +133,13 @@ runs:
     - name: Unit-test that SVG screenshots are one line (test/svgshot.test.mjs)
       shell: bash
       run: node --test test/svgshot.test.mjs
+    # The screenshot review tool (scripts/shot_review.mjs): its session, what
+    # its pages show, its writes under a scratch docs folder, and its server,
+    # followed through a stand-in run, with its commit in a scratch repository.
+    # No IDE, no browser, no built tree; git. About 3 s.
+    - name: Unit-test the screenshot review tool (test/shot-review.test.mjs)
+      shell: bash
+      run: node --test test/shot-review.test.mjs
     # check_examples.mjs's probes: batching, crash isolation through a fake
     # lane, the canaries and the fence classifier. check_examples.mjs needs a
     # twinBASIC install, which CI has not; its probes need none.

.gitignore

@@ -46,3 +46,7 @@ indexer/.packages/
 # shoot_docs.mjs --svg: each picture's bundle (scripts/svgshot/bundle.mjs), what its SVG
 # is drawn from, for scripts/svgshot/replay.mjs. Bundles hold the Windows user name.
 /.svgshot-bundles/
+
+# scripts/shot_review.mjs: the screenshot review's session and its runs' stages
+# (scripts/lib/shot-session.mjs), which hold the Windows user name.
+/.shot-review/

WIP.Harness.md

@@ -1206,7 +1206,26 @@ The recent lists are left alone: `test/ide/recent-projects-copies.test.mjs` need
 A probe of 50 launches hooked 49. The one miss was a page whose document began before the script was
 added. `attachIde` therefore checks `window.__tbDefaults`, the marker the script sets (it lists the keys
 answered, never their values), and reloads the page once when it is missing: the hook's session still holds
-the script, the reload takes about 40 ms, and the UI and the command-line project come back. A marker still
+the script, the reload takes about 40 ms, and the UI and the command-line project come back. The reload
+waits for the hook to be installed (`hook.ready`): the hook connects on its own, and in a `shoot_docs
+--jobs 10` run on BETA 1033 the help setup's page was reloaded before it had attached, loaded unhooked
+again, and failed the setup. `ready` also waits for the pages being prepared: a page that existed
+before the auto-attach is attached by `setAutoAttach` itself and prepared from its event, which `ready`
+did not wait for, so in another `--jobs 10` run on BETA 1033 (2026-11-01) a debugging setup's page was
+reloaded before its script was added, and failed the setup the same way. A page that could not be
+prepared is named in the error. That was not the whole cause: the next `--jobs 10` run failed a
+sample setup the same way with every page prepared, for a reason still unknown. So `checkDefaults`
+also adds the script on its own connection to the page before the reload, which is open while the
+page reloads whatever became of the hook's session, and a marker still missing after that reports
+the page's address and state, the last check's error, the check's steps and the hook's (`trace`:
+connected, each page attached and prepared, ready, a closed connection), each with its time. Those
+named the cause in a `--jobs 16` retake on BETA 1033 (2026-11-02, settings-webview2), and likely the
+sample setup's too: `attach` takes the target listed as `main.htm`, which it is while its navigation
+there is still pending, so the check found `about:blank` with no marker, and its reload loaded
+`about:blank` again and cancelled the navigation (the page "about:blank, complete" after the reload,
+every page prepared). So `checkDefaults` first waits, a minute at most, for the page to commit
+`main.htm`, whose document may then have run the hook after all, and fails with "its page never loaded
+main.htm" rather than reload a page that has not. A marker still
 missing after that is a harness error, exit 2, since the run would have the user's settings. The hook's
 connection lives as long as the process, so a `tbbuild --keep` IDE is hooked until `tbbuild` ends.
 

WIP.HelpAddin.md

@@ -1186,7 +1186,12 @@ not: a restart saves a harness about a second against opening a new IDE.
      the add-in also removes `WEBVIEW2_USER_DATA_FOLDER` and
      `WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS` from the compiler's environment (P19), and
      starts the control with the DevTools port in `TB_DOCS_HELP_WINDOW_PORT`, through which
-     the lane operates the window's page. The `%LOCALAPPDATA%` path is not run by any lane.
+     the lane operates the window's page, and with the further arguments in
+     `TB_DOCS_HELP_WINDOW_ARGS` beside it: `shoot_docs`'s help setup passes
+     `--force-device-scale-factor=1`, without which, on a display scaled to 150%, the page's
+     DOM snapshot is in the display's pixels and Help_Window's SVG is drawn 1.5 times too large
+     (the help lane passes none, so that it tests the window at the display's scale). The
+     `%LOCALAPPDATA%` path is not run by any lane.
    - **The lanes** read the add-in's test-switch lines: `window shown`, `window hidden`,
      `window state max|normal|min`, `window drag` and `window chrome custom|native style
      <hex of GWL_STYLE>`. They check the bar's one row and the four buttons, no `WS_CAPTION`