fix(#3151): stop emitting effort: into skill frontmatter (cache invalidation) (#3425)

Claude Code applies SKILL.md effort: as output_config.effort; any change from
the session baseline invalidates the prompt cache at BOTH scope boundaries
(entry + exit, the latter often machine-fired via subagent-completion
notification). The reporter's owned measurement confirms it: /gsd-progress
(effort:low) in a medium session → cache_creation 63,404 (entry) + 18,589
(exit), while a no-effort skill shows none. ~76% of invocations paid in full.

Fix (trek-e AC#2/AC#4): convertClaudeCommandToClaudeSkill no longer emits
effort: into Claude-runtime skill frontmatter (src/runtime-artifact-conversion.cts
+ duplicated bin/install.js). normalizeClaudeSkillEffort removed (dead). The six
declaring skills (plan-phase/execute-phase/autonomous/next/progress/stats) no
longer carry effort. Source command files keep effort (input, used elsewhere);
the separate agent-effort surface (#3160) is untouched.

Tests: install-runtime-artifacts #769 block flipped to assert effort is ABSENT
from installed SKILL.md + converter output (the AC#4 behavioral coverage).

Co-authored-by: sim <sim@local>

tests/install-runtime-artifacts.test.cjs

@@ -3388,50 +3388,22 @@ describe('#769/#1319 convertClaudeCommandToClaudeSkill: preserves context and em
       `SKILL.md frontmatter must include context: fork\nActual frontmatter:\n${fm}`);
   });
 
-  test('normalizes effort: xhigh/max to effort: high in emitted SKILL.md frontmatter (#1319/#3039)', () => {
-    const input = [
-      '---',
-      'name: gsd:test-heavy',
-      'description: Test heavy skill',
-      'context: fork',
-      'effort: xhigh',
-      'allowed-tools:',
-      '  - Read',
-      '  - Bash',
-      '---',
-      '',
-      'Heavy skill body.',
-    ].join('\n');
-
-    const result = convertClaudeCommandToClaudeSkill(input, 'test-heavy');
-    const end = result.indexOf('---', 3);
-    const fm = result.substring(3, end);
-
-    assert.match(fm, /^effort:[ \t]*high$/m,
-      `SKILL.md frontmatter must include portable effort: high (#3039)\nActual frontmatter:\n${fm}`);
-    assert.doesNotMatch(fm, /^effort:[ \t]*(xhigh|max)$/m,
-      `SKILL.md frontmatter must not include rejected effort: xhigh or max (#1319/#3039)\nActual frontmatter:\n${fm}`);
-  });
-
-  test('preserves effort: low in emitted SKILL.md frontmatter', () => {
-    const input = [
-      '---',
-      'name: gsd:test-light',
-      'description: Test light skill',
-      'effort: low',
-      'allowed-tools:',
-      '  - Read',
-      '---',
-      '',
-      'Light skill body.',
-    ].join('\n');
-
-    const result = convertClaudeCommandToClaudeSkill(input, 'test-light');
-    const end = result.indexOf('---', 3);
-    const fm = result.substring(3, end);
-
-    assert.match(fm, /^effort:[ \t]*low$/m,
-      `SKILL.md frontmatter must include effort: low\nActual frontmatter:\n${fm}`);
+  test('#3151: does NOT emit effort: into SKILL.md frontmatter (a static effort value invalidates the caller\'s prompt cache)', () => {
+    // Whatever effort the source command declares, the installed SKILL.md must
+    // NOT carry it: Claude Code applies SKILL.md `effort:` as output_config.effort,
+    // and any change from the session baseline invalidates the prompt cache at both
+    // scope boundaries (entry + exit). Verified by the reporter's owned measurement.
+    const inputs = [
+      ['xhigh source', '---\nname: gsd:test-heavy\ndescription: Heavy\ncontext: fork\neffort: xhigh\nallowed-tools:\n  - Read\n---\n\nBody.\n'],
+      ['low source', '---\nname: gsd:test-light\ndescription: Light\neffort: low\nallowed-tools:\n  - Read\n---\n\nBody.\n'],
+    ];
+    for (const [label, input] of inputs) {
+      const result = convertClaudeCommandToClaudeSkill(input, label === 'xhigh source' ? 'test-heavy' : 'test-light');
+      const end = result.indexOf('---', 3);
+      const fm = result.substring(3, end);
+      assert.doesNotMatch(fm, /^effort:/m,
+        `SKILL.md frontmatter must NOT include effort: for ${label} (#3151)\nActual frontmatter:\n${fm}`);
+    }
   });
 
   test('does NOT emit context: or effort: when absent from source', () => {
@@ -3461,7 +3433,7 @@ describe('#769/#1319 convertClaudeCommandToClaudeSkill: preserves context and em
 
 // #921/#922: after install, spawning orchestrators must NOT carry context: fork
 // in their emitted SKILL.md. #1319: heavyweight skills must use portable max effort.
-describe('#769/#921/#1319 Claude global install: spawning-orchestrator SKILL.md files have effort: high (clamped from max) but NOT context: fork', () => {
+describe('#769/#921/#3151 Claude global install: SKILL.md files emit NO effort (#3151 — static effort invalidates caller cache) and NOT context: fork', () => {
   let tmpDir;
   let claudeHome;
 
@@ -3483,14 +3455,12 @@ describe('#769/#921/#1319 Claude global install: spawning-orchestrator SKILL.md
       `gsd-autonomous is a spawning orchestrator; its SKILL.md must NOT have context: fork (#921)\nActual:\n${fm}`);
   });
 
-  test('gsd-autonomous SKILL.md has effort: max after global install (#1319)', () => {
+  test('gsd-autonomous SKILL.md does NOT emit effort: after global install (#3151)', () => {
     runClaudeGlobalInstall(claudeHome);
     const skillPath = flatSkillPath(path.join(claudeHome, 'skills'),'autonomous');
     const fm = readFrontmatter(skillPath);
-    assert.match(fm, /^effort:[ \t]*high$/m,
-      `gsd-autonomous SKILL.md must have effort: high\nActual:\n${fm}`);
-    assert.doesNotMatch(fm, /^effort:[ \t]*xhigh$/m,
-      `gsd-autonomous SKILL.md must not have rejected effort: xhigh or max (#1319/#3039)\nActual:\n${fm}`);
+    assert.doesNotMatch(fm, /^effort:/m,
+      `gsd-autonomous SKILL.md must NOT emit effort: (#3151 — a static value invalidates the caller's prompt cache)\nActual:\n${fm}`);
   });
 
   test('gsd-execute-phase SKILL.md does NOT have context: fork after global install (#921)', () => {
@@ -3501,14 +3471,12 @@ describe('#769/#921/#1319 Claude global install: spawning-orchestrator SKILL.md
       `gsd-execute-phase is a spawning orchestrator; its SKILL.md must NOT have context: fork (#921)\nActual:\n${fm}`);
   });
 
-  test('gsd-execute-phase SKILL.md has effort: max after global install (#1319)', () => {
+  test('gsd-execute-phase SKILL.md does NOT emit effort: after global install (#3151)', () => {
     runClaudeGlobalInstall(claudeHome);
     const skillPath = flatSkillPath(path.join(claudeHome, 'skills'),'execute-phase');
     const fm = readFrontmatter(skillPath);
-    assert.match(fm, /^effort:[ \t]*high$/m,
-      `gsd-execute-phase SKILL.md must have effort: high\nActual:\n${fm}`);
-    assert.doesNotMatch(fm, /^effort:[ \t]*xhigh$/m,
-      `gsd-execute-phase SKILL.md must not have rejected effort: xhigh or max (#1319/#3039)\nActual:\n${fm}`);
+    assert.doesNotMatch(fm, /^effort:/m,
+      `gsd-execute-phase SKILL.md must NOT emit effort: (#3151)\nActual:\n${fm}`);
   });
 
   test('gsd-plan-phase SKILL.md does NOT have context: fork after global install (#921)', () => {
@@ -3519,30 +3487,28 @@ describe('#769/#921/#1319 Claude global install: spawning-orchestrator SKILL.md
       `gsd-plan-phase is a spawning orchestrator; its SKILL.md must NOT have context: fork (#921)\nActual:\n${fm}`);
   });
 
-  test('gsd-plan-phase SKILL.md has effort: max after global install (#1319)', () => {
+  test('gsd-plan-phase SKILL.md does NOT emit effort: after global install (#3151)', () => {
     runClaudeGlobalInstall(claudeHome);
     const skillPath = flatSkillPath(path.join(claudeHome, 'skills'),'plan-phase');
     const fm = readFrontmatter(skillPath);
-    assert.match(fm, /^effort:[ \t]*high$/m,
-      `gsd-plan-phase SKILL.md must have effort: high\nActual:\n${fm}`);
-    assert.doesNotMatch(fm, /^effort:[ \t]*xhigh$/m,
-      `gsd-plan-phase SKILL.md must not have rejected effort: xhigh or max (#1319/#3039)\nActual:\n${fm}`);
+    assert.doesNotMatch(fm, /^effort:/m,
+      `gsd-plan-phase SKILL.md must NOT emit effort: (#3151)\nActual:\n${fm}`);
   });
 
-  test('gsd-progress SKILL.md has effort: low after global install', () => {
+  test('gsd-progress SKILL.md does NOT emit effort: after global install (#3151)', () => {
     runClaudeGlobalInstall(claudeHome);
     const skillPath = flatSkillPath(path.join(claudeHome, 'skills'),'progress');
     const fm = readFrontmatter(skillPath);
-    assert.match(fm, /^effort:[ \t]*low$/m,
-      `gsd-progress SKILL.md must have effort: low\nActual:\n${fm}`);
+    assert.doesNotMatch(fm, /^effort:/m,
+      `gsd-progress SKILL.md must NOT emit effort: (#3151)\nActual:\n${fm}`);
   });
 
-  test('gsd-stats SKILL.md has effort: low after global install', () => {
+  test('gsd-stats SKILL.md does NOT emit effort: after global install (#3151)', () => {
     runClaudeGlobalInstall(claudeHome);
     const skillPath = flatSkillPath(path.join(claudeHome, 'skills'),'stats');
     const fm = readFrontmatter(skillPath);
-    assert.match(fm, /^effort:[ \t]*low$/m,
-      `gsd-stats SKILL.md must have effort: low\nActual:\n${fm}`);
+    assert.doesNotMatch(fm, /^effort:/m,
+      `gsd-stats SKILL.md must NOT emit effort: (#3151)\nActual:\n${fm}`);
   });
 });
   });