perf(gateguard): profile a change only when used and check its window first

scripts/hooks/gateguard-fact-force.js

@@ -1674,6 +1674,11 @@ function countTrivialAllow() {
   return saveState({ ...state, trivial_allows: getTrivialAllowCount(state) + 1 });
 }
 
+// see docs/gateguard/change-profile.md#when-a-change-is-profiled
+function needsProfile(toolName, cls) {
+  return targetClass().questionsUseProfile(cls) || ((toolName === 'Edit' || toolName === 'MultiEdit') && TRIVIAL_CLASSES.has(cls)) || isMetricsEnabled();
+}
+
 function isTrivialChange(cls, restricted, profile) {
   return !restricted && TRIVIAL_CLASSES.has(cls) && Boolean(profile) && profile.known === true && profile.trivial === true;
 }
@@ -2332,7 +2337,9 @@ function gate(rawInput) {
         recordDecision('credit', 'prior-search', { target: filePath, cls, sensitive });
         return { additionalContext: creditNote(credit, filePath), exitCode: 0 };
       }
-      const profile = restricted || toolName === 'NotebookEdit' ? null : changeProfileFor(toolName, filePath, [toolInput], toolInput.content, data);
+      const profile = restricted || toolName === 'NotebookEdit' || !needsProfile(toolName, cls)
+        ? null
+        : changeProfileFor(toolName, filePath, [toolInput], toolInput.content, data);
       if (toolName === 'Edit' && isTrivialChange(cls, restricted, profile)) {
         if (!countTrivialAllow()) {
           return allowWithStateWarning();
@@ -2406,7 +2413,9 @@ function gate(rawInput) {
           notes.push(creditNote(credit, filePath));
           continue;
         }
-        const profile = restricted ? null : changeProfileFor('Edit', filePath, entriesFor(edits, fileKey, data), undefined, data);
+        const profile = restricted || !needsProfile('MultiEdit', cls)
+          ? null
+          : changeProfileFor('Edit', filePath, entriesFor(edits, fileKey, data), undefined, data);
         if (isTrivialChange(cls, restricted, profile)) {
           if (!countTrivialAllow()) {
             return allowWithStateWarning();

scripts/lib/gateguard-file-context.js

@@ -708,12 +708,13 @@ function trivialInFile(pairs, fileText, spec) {
     const start = windowStart(text, found.first);
     const end = windowEnd(text, found.last + oldString.length);
     work += start + 2 * (end - start);
-    if (end - start > MAX_WINDOW_CHARS || work > MAX_CONTEXT_WORK || !spec.startsFresh(text.slice(0, start), spec)) return false;
+    if (end - start > MAX_WINDOW_CHARS || work > MAX_CONTEXT_WORK) return false;
     const before = text.slice(start, end);
     const after = replaceAll
       ? before.split(oldString).join(newString)
       : `${text.slice(start, found.first)}${newString}${text.slice(found.first + oldString.length, end)}`;
-    if (!isTrivialEdit(before, after, spec)) return false;
+    // see docs/gateguard/change-profile.md#file-context
+    if (!isTrivialEdit(before, after, spec) || !spec.startsFresh(text.slice(0, start), spec)) return false;
     text = `${text.slice(0, start)}${after}${text.slice(end)}`;
     if (text.length > MAX_FILE_CHARS) return false;
   }

scripts/lib/gateguard-target-class.js

@@ -193,6 +193,11 @@ function codeQuestionIds(isWrite, profile) {
 }
 
 /** Stable ids of the first-touch questions for a class, action and change profile. */
+/** True when a class's questions depend on the change profile. */
+function questionsUseProfile(cls) {
+  return !Object.hasOwn(CLASS_QUESTION_IDS, cls);
+}
+
 function questionIdsFor(cls, isWrite, profile) {
   const ids = Object.hasOwn(CLASS_QUESTION_IDS, cls) ? CLASS_QUESTION_IDS[cls](Boolean(isWrite)) : codeQuestionIds(Boolean(isWrite), profile);
   return [...ids, 'quote-instruction'];
@@ -407,6 +412,7 @@ function collapseGateDir(filePath, data, cls) {
 }
 
 module.exports = {
+  questionsUseProfile,
   WINDOWS_PATH_PATTERN,
   COLLAPSIBLE_CLASSES,
   CLASS_QUESTIONS,