fix: stop filterSkillBodyForMode from swallowing rule bullets that start with a mode word (#571)

filterSkillBodyForMode is the shared filter every host adapter (Claude
hooks, Pi, OpenCode, the MCP server, Hermes) uses to trim the ponytail
skill body down to the active intensity. Its worked-example detection
matched any bullet shaped "- label: text" and treated it as a
mode-specific example whenever the label happened to normalize to a
mode name (lite/full/ultra/off) -- silently dropping it in every other
mode.

The current SKILL.md doesn't trip this today (its only such bullets are
the three real worked examples), but it's a landmine: an ordinary rule
bullet added later that happens to start with "Full:" or "Lite:" would
vanish from every other mode's instructions with no warning, in the one
code path every adapter shares. Confirmed with a real bullet:

  filterSkillBodyForMode('- Full: real rule text.', 'ultra')

silently drops the line before this fix.

All three real worked examples are quoted (`- lite: "..."`); ordinary
rule bullets aren't. Required the quote so only genuine examples are
mode-filtered, and added a regression test plus fixed an existing test
whose synthetic fixture used unquoted examples that don't match the
real file's format.

hooks/ponytail-instructions.js

@@ -25,7 +25,11 @@ function filterSkillBodyForMode(body, mode) {
         if (labelMode) return labelMode === effectiveMode;
       }
 
-      const exampleLabel = line.match(/^-\s*([^:]+):\s*/);
+      // Require a quoted value: every worked example is `- lite: "..."`. Without
+      // this, an ordinary rule bullet that happens to start with a mode word
+      // (e.g. "- Full: ...") is silently dropped in every other mode — it looks
+      // like a worked example but is really prose meant to survive verbatim.
+      const exampleLabel = line.match(/^-\s*([^:]+):\s*"/);
       if (exampleLabel) {
         const labelMode = normalizeMode(exampleLabel[1].trim());
         if (labelMode) return labelMode === effectiveMode;

pi-extension/test/helpers.test.js

@@ -104,7 +104,9 @@ test("readQuietStartup resolves env var, config file, and default in that order"
 });
 
 test("filterSkillBodyForMode keeps only requested intensity examples and rows", () => {
-  const body = `---\nname: ponytail\n---\n| **lite** | keep lite |\n| **full** | keep full |\n| **ultra** | keep ultra |\n- lite: Lite example\n- full: Full example\n- ultra: Ultra example\nOther line`;
+  // Examples are quoted in the real SKILL.md (`- lite: "..."`) — match that
+  // shape here too; see the next test for why the quote is load-bearing.
+  const body = `---\nname: ponytail\n---\n| **lite** | keep lite |\n| **full** | keep full |\n| **ultra** | keep ultra |\n- lite: "Lite example"\n- full: "Full example"\n- ultra: "Ultra example"\nOther line`;
 
   const filtered = filterSkillBodyForMode(body, "ultra");
 
@@ -116,6 +118,20 @@ test("filterSkillBodyForMode keeps only requested intensity examples and rows",
   assert.ok(filtered.includes("Other line"));
 });
 
+test("filterSkillBodyForMode does not drop a rule bullet whose label matches a mode name", () => {
+  // A rule bullet like "- Full: ..." has the same "label: text" shape as a
+  // worked example, but isn't one — it must survive in every mode. Only the
+  // quoted, `- lite: "..."`-style bullets are real per-mode examples.
+  const body = `- Full: do not confuse this rule label with the mode name.\n- Lite: same risk, this is a real rule bullet.\n- lite: "real worked example"\n- ultra: "real worked example"`;
+
+  const filtered = filterSkillBodyForMode(body, "ultra");
+
+  assert.ok(filtered.includes("Full: do not confuse"), "an unquoted rule bullet must not be treated as a mode example");
+  assert.ok(filtered.includes("Lite: same risk"), "an unquoted rule bullet must not be treated as a mode example");
+  assert.ok(!filtered.includes("- lite:"), "the real quoted lite example must still be filtered out in ultra mode");
+  assert.ok(filtered.includes('ultra: "real worked example"'));
+});
+
 test("filterSkillBodyForMode keeps rule bullets that contain a colon", () => {
   // Regression: rule bullets outside the Intensity section (e.g. the
   // "No unrequested abstractions:" rule or the `ponytail:` comment convention)