fix: strip skill expansions from collaboration word counts

/tdd, /ship, /goodnight etc expand into 500+ word skill prompts stored
as "user" messages in the JSONL. The collaboration analyzer was counting
these as human words, making 10-word commands look like Spec Dumps.

Now strips everything from "Base directory for this skill:" to
"ARGUMENTS:", keeping only the user's actual args. Skill invocations
with no args produce empty turns (skipped).

Author: ateeples

sesh/analyzers/collaboration.py

@@ -92,6 +92,16 @@
     re.DOTALL,
 )
 
+# Skill expansion pattern — when user types /tdd or /ship, the JSONL stores
+# the full skill prompt (500+ words) as a "user" message. We need to strip
+# the skill body and keep only the user's actual arguments.
+_SKILL_EXPANSION_RE = re.compile(
+    r"Base directory for this skill:.*?(?=ARGUMENTS:|$)",
+    re.DOTALL,
+)
+# Also strip the ARGUMENTS: prefix itself
+_SKILL_ARGS_PREFIX_RE = re.compile(r"^ARGUMENTS:\s*", re.MULTILINE)
+
 
 # --- Data types ---
 
@@ -245,6 +255,10 @@ def extract_human_turns(path: Path) -> list[HumanTurn]:
             # Strip system noise
             text = _SYSTEM_TAG_RE.sub("", text).strip()
 
+            # Strip skill expansions — keep only the user's actual arguments
+            text = _SKILL_EXPANSION_RE.sub("", text).strip()
+            text = _SKILL_ARGS_PREFIX_RE.sub("", text).strip()
+
             # Skip empty or trivial turns
             if not text or len(text) <= 1:
                 continue

tests/test_collaboration.py

@@ -194,6 +194,45 @@ def test_skips_tool_results(self, tmp_path):
         assert turns[0].text == "Now fix this"
         assert "result data" not in turns[0].text
 
+    def test_strips_skill_expansions_with_args(self, tmp_path):
+        """Skill expansions are stripped, keeping only the user's ARGUMENTS."""
+        path = tmp_path / "session.jsonl"
+        skill_text = (
+            "Base directory for this skill: /path/to/skill\n\n"
+            "# My Skill\n\nThis is a long skill prompt with instructions "
+            "that goes on for many lines and hundreds of words.\n\n"
+            "ARGUMENTS: implement step 5 of the plan"
+        )
+        record = {
+            "type": "user",
+            "timestamp": "2026-03-14T10:00:00Z",
+            "message": {"content": [{"type": "text", "text": skill_text}]}
+        }
+        path.write_text(json.dumps(record))
+        turns = extract_human_turns(path)
+        assert len(turns) == 1
+        assert "implement step 5" in turns[0].text
+        assert "Base directory" not in turns[0].text
+        assert "long skill prompt" not in turns[0].text
+        assert turns[0].word_count < 20  # Just the args, not the 500+ word skill
+
+    def test_strips_skill_expansions_without_args(self, tmp_path):
+        """Skill expansions with no ARGUMENTS produce empty turns (skipped)."""
+        path = tmp_path / "session.jsonl"
+        skill_text = (
+            "Base directory for this skill: /path/to/skill\n\n"
+            "# Goodnight\n\nYou're going to sleep. This is how you tuck yourself in."
+        )
+        record = {
+            "type": "user",
+            "timestamp": "2026-03-14T10:00:00Z",
+            "message": {"content": [{"type": "text", "text": skill_text}]}
+        }
+        path.write_text(json.dumps(record))
+        turns = extract_human_turns(path)
+        # No ARGUMENTS = empty after stripping = skipped
+        assert len(turns) == 0
+
     def test_skips_empty_turns(self, tmp_path):
         """Empty or trivial text is skipped."""
         path = tmp_path / "session.jsonl"