fix ltl semantics and unify action enumeration (#71)

* fix(ltl): give every thunk a construction identity

Two distinct unnamed predicates both described as "Thunk(...)", so obligation
collapse merged their residuals and could drop a live violation. Identity is
assigned at construction and the fields are unexported, so a thunk cannot be
built without one.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(ltl): reduce a thrown-predicate residual instead of panicking

The verifier substitutes an ErrorFormula for the residual of a property whose
predicate threw, and that residual is fed back in on the next step. reduce had
no case for it, so the run crashed. It re-reports the same failure now.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(ltl): make a bounded always the dual of a bounded eventually

G<=n(f) and not F<=n(not f) disagreed on traces where the inner was still
pending when the window closed, so nnf's negation normal form was not semantics
preserving. Both sides now range over the observations at which their inner can
definitely resolve: the eventually keeps a pending inner as a disjunct, and the
always discharges vacuously at window close.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(ltl): arm a one-shot root once per run

A root that carries its own horizon is one obligation for the whole run, not one
per observation. Re-instantiating a top-level eventually monitored G F<=n(p)
instead of F<=n(p) and left one live obligation per step behind; a bounded
always restarted its window every step and never closed.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(verifier): stop wrapping a top-level eventually in always

`eventually(p).within(300, "seconds")` as a property meant "within 300 seconds
of every step", which spawned an obligation per step with its own resolved
deadline. A 553-step run carried 553 of them and serialized a 75 KB residual.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(ltl): serialize the resolved deadline of a bounded window

Two obligations spawned at different steps from one duration-bounded formula
differ only in the deadline the evaluator resolved for them, so they serialized
identically and the trace erased a distinction the evaluator makes. The authored
window stays in amount/unit; the resolved deadline rides alongside.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(verifier): split a witness's origin step from its detection step

A deferred obligation spans two steps: the one that armed it and the one whose
reduction failed. They were conflated under one index, so the extractor snapshot
(which is the detecting step's state) was reported against the origin step.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(runner): record a witness's detection step in the trace

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* feat(replay-ui): show the step a violation was detected at

The witness evidence is the detecting step's state, so say which step that is
and let a reader jump to it.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(verifier): record the extractor state the predicates actually read

On the web path extractor bodies are evaluated in V8 and injected here, but only
the goja value was replaced. The trace diff and the violation witness therefore
described a state no property ever saw.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* refactor(spec): one candidate producer over one target-eligibility rule

Both hosts routed verbs themselves and both policies enumerated their own
actions, and all four drifted. Web sent `swipes` to scrollable containers only,
so swipe-to-dismiss on a list row was reachable on native and unreachable on
web; the model policy folded gestures its own way and could not reach what the
seeded picker drew.

A host now reports facts about every element and never decides which verb may
act on it: targets.ts acceptsTarget owns that for both. pick.ts builtinCandidates
is the single enumeration, and the model policy reads it through
__sanderlingEnumerateBuiltin__ instead of reimplementing it in Go.

Gesture verbs change with it: scrolls stay vertical over scrollable containers,
swipes go free-form in all four directions from any element with real bounds.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(runner): name a builtin scroll by its drag origin

A builtin gesture carries endpoints and no selector, so every scroll rendered as
"Scroll down " in the prompt's recent-action memory and two scrollable regions
were indistinguishable.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(chrome): clear storage over cdp instead of scripting an opaque origin

Launch runs while the tab is still on about:blank, whose opaque origin denies
storage access, so localStorage.clear() threw SecurityError and every web run
died at launch. Storage.clearDataForOrigin needs no navigation. The exception
helper lands here because "Uncaught" is what hid this for so long.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(chrome): enable the swiftshader webgl fallback

Headless Chrome runs with --disable-gpu, and without this flag it refuses the
software WebGL backend: getContext returns null, so a canvas-rendered app paints
nothing and every screenshot is identical black.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* fix(web): resolve testTag through data-testid or id

Compose Multiplatform emits its testTag into the element id, which the native
table already accepts via the resource-id alias. The two web selector tables
were the only place that rejected it.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* test(spec): type-check the spec api as part of make test

The fake runtime in api.test.ts did not return a chainable handle from extract,
so the file had not type-checked since named() was added. Wiring the check into
make test stops it drifting again.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

* docs(manual): one-shot eventually and the gesture verbs

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

pkg/spec/test/web-runtime.test.ts

@@ -83,78 +83,60 @@ test("installRuntime defined the host-invoked globals", () => {
   assert.equal(typeof g.__sanderling__, "object");
 });
 
-// A button and a text input, each with a deterministic bounding box, exercise
-// the per-verb selector routing without a full DOM.
-function fakeElement(tag: string, rect: { x: number; y: number; w: number; h: number }) {
-  return {
-    tagName: tag.toUpperCase(),
-    disabled: false,
-    isContentEditable: false,
-    type: tag === "input" ? "text" : "",
-    scrollHeight: 0,
-    clientHeight: 0,
-    scrollWidth: 0,
-    clientWidth: 0,
-    getBoundingClientRect: () => ({
-      left: rect.x,
-      top: rect.y,
-      width: rect.w,
-      height: rect.h,
-      right: rect.x + rect.w,
-      bottom: rect.y + rect.h,
-    }),
-  };
-}
+const { fakeElement, withFakeDocument } = await import("./web-dom-harness.ts");
 
-function withFakeDocument(map: Record<string, unknown[]>, run: () => void) {
-  const g = globalThis as Record<string, unknown>;
-  const original = g.document;
-  g.document = {
-    querySelectorAll: (selector: string) => map[selector] ?? [],
-    scrollingElement: null,
-    documentElement: null,
-  };
-  try {
-    run();
-  } finally {
-    g.document = original;
-  }
-}
-
-test("queryCandidates routes taps to the tappable selector set", () => {
-  const button = fakeElement("button", { x: 10, y: 20, w: 40, h: 8 });
-  withFakeDocument(
-    { 'a, button, input, select, textarea, [role="button"], [onclick]': [button] },
-    () => {
-      __testing__.resetCandidateCache();
-      const candidates = host.queryCandidates("taps");
-      assert.equal(candidates.length, 1);
-      assert.deepEqual({ x: candidates[0]!.x, y: candidates[0]!.y }, { x: 30, y: 24 });
-    },
-  );
-});
-
-test("queryCandidates routes typing to editable inputs only", () => {
-  const input = fakeElement("input", { x: 0, y: 0, w: 100, h: 20 });
-  withFakeDocument({ "input, textarea, [contenteditable]": [input] }, () => {
-    __testing__.resetCandidateCache();
-    const candidates = host.queryCandidates("typing");
-    assert.equal(candidates.length, 1);
-    assert.deepEqual({ x: candidates[0]!.x, y: candidates[0]!.y }, { x: 50, y: 10 });
+// The host reports facts and never routes verbs: which of these a verb may act
+// on is decided by the shared rule in src/targets.ts, exercised across both
+// engines by host-parity.test.ts.
+test("queryTargets reports the tappable selector set as clickable", () => {
+  const button = fakeElement({ tag: "button", x: 10, y: 20, width: 40, height: 8, clickable: true });
+  const plain = fakeElement({ tag: "div", x: 0, y: 0, width: 100, height: 100 });
+  withFakeDocument([button, plain], () => {
+    const targets = host.queryTargets();
+    assert.equal(targets.length, 2);
+    assert.equal(targets[0]!.clickable, true);
+    assert.deepEqual({ x: targets[0]!.x, y: targets[0]!.y }, { x: 30, y: 24 });
+    assert.equal(targets[1]!.clickable, false);
   });
 });
 
-test("queryCandidates caches within a tick until reset", () => {
-  const first = fakeElement("button", { x: 0, y: 0, w: 10, h: 10 });
-  withFakeDocument(
-    { 'a, button, input, select, textarea, [role="button"], [onclick]': [first] },
-    () => {
-      __testing__.resetCandidateCache();
-      const a = host.queryCandidates("taps");
-      const b = host.queryCandidates("taps");
-      assert.equal(a, b);
-    },
-  );
+test("queryTargets reports only real text inputs as editable", () => {
+  const input = fakeElement({ tag: "input", x: 0, y: 0, width: 100, height: 20, editable: true });
+  const checkbox = fakeElement({ tag: "input", x: 0, y: 40, width: 20, height: 20, editable: true });
+  checkbox.type = "checkbox";
+  withFakeDocument([input, checkbox], () => {
+    const targets = host.queryTargets();
+    assert.equal(targets[0]!.editable, true);
+    assert.deepEqual({ x: targets[0]!.x, y: targets[0]!.y }, { x: 50, y: 10 });
+    assert.equal(targets[1]!.editable, false);
+  });
+});
+
+// A disabled control used to be dropped from every verb's candidates, because
+// the web host folded `disabled` into its visibility check. It is a fact of its
+// own now, so `taps` still skips it while `swipes` can still start on it, which
+// is what the native host has always done.
+test("queryTargets reports a disabled control rather than dropping it", () => {
+  const disabled = fakeElement({
+    tag: "button", x: 0, y: 0, width: 40, height: 20, clickable: true, disabled: true,
+  });
+  withFakeDocument([disabled], () => {
+    const targets = host.queryTargets();
+    assert.equal(targets.length, 1);
+    assert.equal(targets[0]!.clickable, true);
+    assert.equal(targets[0]!.enabled, false);
+  });
+});
+
+test("queryTargets caches within a tick until reset", () => {
+  const button = fakeElement({ tag: "button", x: 0, y: 0, width: 10, height: 10, clickable: true });
+  withFakeDocument([button], () => {
+    const first = host.queryTargets();
+    const second = host.queryTargets();
+    assert.equal(first, second);
+    __testing__.resetTargetCache();
+    assert.notEqual(host.queryTargets(), first);
+  });
 });
 
 // evaluateExtractors builds State, which references document and window.
@@ -328,6 +310,23 @@ test("selectorFromObject maps known keys to their canonical attribute", () => {
   });
 });
 
+// Compose Multiplatform emits its testTag into `id`, which the native table
+// already accepts via the resource-id alias. The web table must not be the one
+// place that rejects it.
+test("selectorFromObject resolves testTag through data-testid or id", () => {
+  assert.deepEqual(selectorFromObject({ testTag: "LoginSubmit" }), {
+    css: `:is([data-testid="LoginSubmit"], [id="LoginSubmit"])`,
+  });
+});
+
+// Multi-key selectors concatenate their parts into one compound, so the
+// two-attribute testTag match has to stay a single compound piece.
+test("selectorFromObject composes testTag with a second key", () => {
+  assert.deepEqual(selectorFromObject({ testTag: "Row", "aria-label": "first" }), {
+    css: `:is([data-testid="Row"], [id="Row"])[aria-label="first"]`,
+  });
+});
+
 test("selectorFromObject falls back to a literal attribute for unknown keys", () => {
   assert.deepEqual(selectorFromObject({ "data-foo": "bar" }), {
     css: `[data-foo="bar"]`,