diff --git a/CLAUDE.md b/CLAUDE.md
index 3f905d4..0239bde 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -1,12 +1,20 @@
-# PhysCom — Physical Combinatorics
+# CLAUDE.md
 
-Innovation discovery engine: generate entity combinations, filter by physical constraints, score against domain-specific metrics, rank results.
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## What this project is
+
+PhysCom (Physical Combinatorics) — innovation discovery engine that generates entity combinations across dimensions (e.g. platform × power_source), filters by physical constraints, scores against domain-specific metrics, and ranks results. Includes a CLI, a Flask/HTMX web UI, and a 5-pass pipeline (constraints → estimation → scoring → LLM review → human review).
 
 ## Commands
 
-- **Tests**: `python -m pytest tests/ -q` (48 tests, ~3s). Run after every change.
+- **Install**: `pip install -e ".[dev,web]"` (editable install with test and web deps)
+- **Tests (all)**: `python -m pytest tests/ -q` (48 tests, ~5s). Run after every change.
+- **Single test file**: `python -m pytest tests/test_scorer.py -q`
+- **Single test**: `python -m pytest tests/test_scorer.py::test_score_combination -q`
 - **Web dev server**: `python -m physcom_web`
-- **CLI**: `python -m physcom`
+- **CLI**: `python -m physcom` (or `physcom` if installed)
+- **Docker**: `docker compose up web` / `docker compose run cli physcom seed`
 - **Seed data**: loaded automatically on first DB init (SQLite, `physcom.db` or `$PHYSCOM_DB`)
 
 ## Architecture
@@ -53,13 +61,19 @@ tests/                     # pytest, uses seeded_repo fixture from conftest.py
 1. **Pass 1 — Constraints**: `ConstraintResolver.resolve()` → blocked/conditional/valid. Blocked combos get a result row and `continue`.
 2. **Pass 2 — Estimation**: LLM or `_stub_estimate()` → raw metric values. Saved immediately via `save_raw_estimates()` (normalized_score=NULL).
 3. **Pass 3 — Scoring**: `Scorer.score_combination()` → log-normalized scores + weighted geometric mean composite. Saves via `save_scores()` + `save_result()`.
-4. **Pass 4 — LLM Review**: Only for above-threshold combos with an LLM provider.
+4. **Pass 4 — LLM Review**: Only for above-threshold combos with an LLM provider. No real provider yet (only `MockLLMProvider`).
 5. **Pass 5 — Human Review**: Manual via web UI results page.
 
+## Testing
+
+- Tests use `seeded_repo` fixture (in-memory SQLite with transport seed data: 9 platforms, 9 power sources, 2 domains). There's also a bare `repo` fixture for tests that seed their own data.
+- Individual entity fixtures (walking, bicycle, spaceship, solar_sail, etc.) are defined in `conftest.py`.
+
 ## Conventions
 
 - Python 3.11+, `from __future__ import annotations` everywhere.
 - Dataclasses for models, no ORM.
-- Tests use `seeded_repo` fixture (in-memory SQLite with transport seed data).
 - Don't use `cd` in Bash commands — run from the working directory so pre-approved permission patterns match.
 - Don't add docstrings/comments/type annotations to code you didn't change.
+- `INSERT OR IGNORE` won't update existing rows — if adding a new column/field to seed data, also add an UPDATE for backfill.
+- Jinja2 `0.0` is falsy — use `is not none` not `if value` when displaying scores that can legitimately be zero.
diff --git a/src/physcom/cli.py b/src/physcom/cli.py
index 5bf0bcc..cbb414f 100644
--- a/src/physcom/cli.py
+++ b/src/physcom/cli.py
@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import json
 from pathlib import Path
 
 import click
diff --git a/src/physcom/db/repository.py b/src/physcom/db/repository.py
index 6a2ac9e..4f50bae 100644
--- a/src/physcom/db/repository.py
+++ b/src/physcom/db/repository.py
@@ -204,7 +204,7 @@ class Repository:
         if not row:
             return None
         weights = self.conn.execute(
-            """SELECT m.name, dmw.weight, dmw.norm_min, dmw.norm_max, dmw.metric_id
+            """SELECT m.name, m.unit, dmw.weight, dmw.norm_min, dmw.norm_max, dmw.metric_id
                FROM domain_metric_weights dmw
                JOIN metrics m ON dmw.metric_id = m.id
                WHERE dmw.domain_id = ?""",
@@ -218,7 +218,7 @@ class Repository:
                 MetricBound(
                     metric_name=w["name"], weight=w["weight"],
                     norm_min=w["norm_min"], norm_max=w["norm_max"],
-                    metric_id=w["metric_id"],
+                    metric_id=w["metric_id"], unit=w["unit"] or "",
                 )
                 for w in weights
             ],
@@ -411,26 +411,17 @@ class Repository:
 
     def get_all_results(self, domain_name: str, status: str | None = None) -> list[dict]:
         """Return all results for a domain, optionally filtered by combo status."""
+        query = """SELECT cr.*, c.hash, c.status as combo_status, d.name as domain_name
+                   FROM combination_results cr
+                   JOIN combinations c ON cr.combination_id = c.id
+                   JOIN domains d ON cr.domain_id = d.id
+                   WHERE d.name = ?"""
+        params: list = [domain_name]
         if status:
-            rows = self.conn.execute(
-                """SELECT cr.*, c.hash, c.status as combo_status, d.name as domain_name
-                   FROM combination_results cr
-                   JOIN combinations c ON cr.combination_id = c.id
-                   JOIN domains d ON cr.domain_id = d.id
-                   WHERE d.name = ? AND c.status = ?
-                   ORDER BY cr.composite_score DESC""",
-                (domain_name, status),
-            ).fetchall()
-        else:
-            rows = self.conn.execute(
-                """SELECT cr.*, c.hash, c.status as combo_status, d.name as domain_name
-                   FROM combination_results cr
-                   JOIN combinations c ON cr.combination_id = c.id
-                   JOIN domains d ON cr.domain_id = d.id
-                   WHERE d.name = ?
-                   ORDER BY cr.composite_score DESC""",
-                (domain_name,),
-            ).fetchall()
+            query += " AND c.status = ?"
+            params.append(status)
+        query += " ORDER BY cr.composite_score DESC"
+        rows = self.conn.execute(query, params).fetchall()
         results = []
         for r in rows:
             combo = self.get_combination(r["combination_id"])
diff --git a/src/physcom/engine/combinator.py b/src/physcom/engine/combinator.py
index 2a6bd61..4151995 100644
--- a/src/physcom/engine/combinator.py
+++ b/src/physcom/engine/combinator.py
@@ -25,9 +25,7 @@ def generate_combinations(
             raise ValueError(f"No entities found for dimension '{dim}'")
         entity_groups.append(entities)
 
-    combinations = []
-    for entity_tuple in itertools.product(*entity_groups):
-        combo = Combination(entities=list(entity_tuple))
-        combinations.append(combo)
-
-    return combinations
+    return [
+        Combination(entities=list(entity_tuple))
+        for entity_tuple in itertools.product(*entity_groups)
+    ]
diff --git a/src/physcom/engine/pipeline.py b/src/physcom/engine/pipeline.py
index e69b7cb..4aadf0f 100644
--- a/src/physcom/engine/pipeline.py
+++ b/src/physcom/engine/pipeline.py
@@ -157,14 +157,13 @@ class Pipeline:
                         result.pass1_blocked += 1
                         self._update_run_counters(run_id, result, current_pass=1)
                         continue  # blocked — skip remaining passes
-                    elif cr.status == "conditional":
-                        combo.status = "valid"
-                        self.repo.update_combination_status(combo.id, "valid")
-                        result.pass1_conditional += 1
                     else:
                         combo.status = "valid"
                         self.repo.update_combination_status(combo.id, "valid")
-                        result.pass1_valid += 1
+                        if cr.status == "conditional":
+                            result.pass1_conditional += 1
+                        else:
+                            result.pass1_valid += 1
 
                     self._update_run_counters(run_id, result, current_pass=1)
                 elif 1 in passes:
diff --git a/src/physcom/seed/transport_example.py b/src/physcom/seed/transport_example.py
index c8181ce..75bb9cc 100644
--- a/src/physcom/seed/transport_example.py
+++ b/src/physcom/seed/transport_example.py
@@ -265,22 +265,35 @@ INTERPLANETARY = Domain(
 
 
 def load_transport_seed(repo) -> dict:
-    """Load all transport seed data into the repository. Returns counts."""
+    """Load all transport seed data into the repository. Idempotent — safe to re-run."""
+    import sqlite3
     from physcom.db.repository import Repository
     repo: Repository
 
     counts = {"platforms": 0, "power_sources": 0, "domains": 0}
 
     for entity in PLATFORMS:
-        repo.add_entity(entity)
-        counts["platforms"] += 1
+        try:
+            repo.add_entity(entity)
+            counts["platforms"] += 1
+        except sqlite3.IntegrityError:
+            pass
 
     for entity in POWER_SOURCES:
-        repo.add_entity(entity)
-        counts["power_sources"] += 1
+        try:
+            repo.add_entity(entity)
+            counts["power_sources"] += 1
+        except sqlite3.IntegrityError:
+            pass
 
-    repo.add_domain(URBAN_COMMUTING)
-    repo.add_domain(INTERPLANETARY)
-    counts["domains"] = 2
+    for domain in (URBAN_COMMUTING, INTERPLANETARY):
+        try:
+            repo.add_domain(domain)
+            counts["domains"] += 1
+        except sqlite3.IntegrityError:
+            pass
+        # Backfill metric units on existing DBs (ensure_metric is idempotent).
+        for mb in domain.metric_bounds:
+            repo.ensure_metric(mb.metric_name, unit=mb.unit)
 
     return counts
diff --git a/src/physcom_web/templates/domains/list.html b/src/physcom_web/templates/domains/list.html
index 5b965b3..b69f2cc 100644
--- a/src/physcom_web/templates/domains/list.html
+++ b/src/physcom_web/templates/domains/list.html
@@ -13,12 +13,13 @@
     <p>{{ d.description }}</p>
     <table>
       <thead>
-        <tr><th>Metric</th><th>Weight</th><th>Norm Min</th><th>Norm Max</th></tr>
+        <tr><th>Metric</th><th>Unit</th><th>Weight</th><th>Norm Min</th><th>Norm Max</th></tr>
       </thead>
       <tbody>
         {% for mb in d.metric_bounds %}
         <tr>
           <td>{{ mb.metric_name }}</td>
+          <td>{{ mb.unit }}</td>
           <td>{{ mb.weight }}</td>
           <td>{{ mb.norm_min }}</td>
           <td>{{ mb.norm_max }}</td>
diff --git a/tests/conftest.py b/tests/conftest.py
index 8703118..2a1b2a4 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -2,8 +2,6 @@
 
 from __future__ import annotations
 
-import sqlite3
-
 import pytest
 
 from physcom.db.schema import init_db
diff --git a/tests/test_pipeline_async.py b/tests/test_pipeline_async.py
index 8d7ff7e..4e0616e 100644
--- a/tests/test_pipeline_async.py
+++ b/tests/test_pipeline_async.py
@@ -1,7 +1,5 @@
 """Tests for async pipeline: resume, cancellation, status guard, run lifecycle."""
 
-import json
-
 from physcom.engine.constraint_resolver import ConstraintResolver
 from physcom.engine.scorer import Scorer
 from physcom.engine.pipeline import Pipeline, CancelledError
@@ -287,7 +285,6 @@ def test_save_combination_loads_existing_status(seeded_repo):
     """save_combination should load the status of an existing combo from DB."""
     repo = seeded_repo
     from physcom.models.combination import Combination
-    from physcom.models.entity import Entity
 
     entities = repo.list_entities(dimension="platform")[:1] + repo.list_entities(dimension="power_source")[:1]
     combo = Combination(entities=entities)