close guardrail gaps and fix the scoring pipeline top to bottom

Constraint resolver: aggregate mass/footprint across a combo instead of
pairwise-only checks, treat medium/atmosphere as agreement not supply/demand,
reduce multi-provider checks by best/sum instead of AND-ing every provider,
fail closed on unrecognized mutex values, add a propulsion-viability
(thrust-to-weight) rule. Seed data updated to match (nuclear/solar-sail
footprint floors, water-medium exclusions, explicit ground/gravity providers).

Domain metric units were stored globally per metric name instead of
per-domain, silently corrupting cost_efficiency for every domain but the
first one seeded — fixed with a schema migration.

Stub estimator's cost_efficiency/safety/availability/reliability were a
backwards formula and flat constants; replaced with heuristics grounded in
each entity's thrust_profile/energy_form/infrastructure.

LLM estimate_physics() now receives each metric's unit and expected range
instead of a bare name, fixing wildly miscalibrated estimates traced back to
the prompt's own hardcoded example anchoring the model to the wrong order of
magnitude. Sharpened the safety-estimation and plausibility-review prompts.
Deduped provider parsing logic into llm/parsing.py.

Web pipeline form can now pick an LLM provider per run instead of only via
server env var.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/physcom/db/repository.py

@@ -233,6 +233,16 @@ class Repository:
         )
         self.conn.commit()
 
+    def backfill_metric_unit(self, domain_name: str, metric_name: str, unit: str) -> None:
+        """Set this domain-metric row's unit — unit is domain-scoped, not global to the metric name."""
+        self.conn.execute(
+            """UPDATE domain_metric_weights SET unit = ?
+               WHERE domain_id = (SELECT id FROM domains WHERE name = ?)
+                 AND metric_id = (SELECT id FROM metrics WHERE name = ?)""",
+            (unit, domain_name, metric_name),
+        )
+        self.conn.commit()
+
     def add_domain(self, domain: Domain) -> Domain:
         cur = self.conn.execute(
             "INSERT INTO domains (name, description) VALUES (?, ?)",
@@ -244,10 +254,10 @@ class Repository:
             mb.metric_id = metric_id
             self.conn.execute(
                 """INSERT INTO domain_metric_weights
-                   (domain_id, metric_id, weight, norm_min, norm_max, lower_is_better)
-                   VALUES (?, ?, ?, ?, ?, ?)""",
+                   (domain_id, metric_id, weight, norm_min, norm_max, lower_is_better, unit)
+                   VALUES (?, ?, ?, ?, ?, ?, ?)""",
                 (domain.id, metric_id, mb.weight, mb.norm_min, mb.norm_max,
-                 int(mb.lower_is_better)),
+                 int(mb.lower_is_better), mb.unit),
             )
         for dc in domain.constraints:
             for val in dc.allowed_values:
@@ -273,7 +283,7 @@ class Repository:
         if not row:
             return None
         weights = self.conn.execute(
-            """SELECT m.name, m.unit, dmw.weight, dmw.norm_min, dmw.norm_max,
+            """SELECT m.name, dmw.unit, dmw.weight, dmw.norm_min, dmw.norm_max,
                       dmw.metric_id, dmw.lower_is_better
                FROM domain_metric_weights dmw
                JOIN metrics m ON dmw.metric_id = m.id
@@ -318,10 +328,10 @@ class Repository:
         mb.metric_id = metric_id
         self.conn.execute(
             """INSERT OR REPLACE INTO domain_metric_weights
-               (domain_id, metric_id, weight, norm_min, norm_max, lower_is_better)
-               VALUES (?, ?, ?, ?, ?, ?)""",
+               (domain_id, metric_id, weight, norm_min, norm_max, lower_is_better, unit)
+               VALUES (?, ?, ?, ?, ?, ?, ?)""",
             (domain_id, metric_id, mb.weight, mb.norm_min, mb.norm_max,
-             int(mb.lower_is_better)),
+             int(mb.lower_is_better), mb.unit),
         )
         self.conn.commit()
         return mb
@@ -332,15 +342,10 @@ class Repository:
     ) -> None:
         self.conn.execute(
             """UPDATE domain_metric_weights
-               SET weight = ?, norm_min = ?, norm_max = ?, lower_is_better = ?
+               SET weight = ?, norm_min = ?, norm_max = ?, lower_is_better = ?, unit = ?
                WHERE domain_id = ? AND metric_id = ?""",
-            (weight, norm_min, norm_max, int(lower_is_better), domain_id, metric_id),
+            (weight, norm_min, norm_max, int(lower_is_better), unit, domain_id, metric_id),
         )
-        if unit:
-            self.conn.execute(
-                "UPDATE metrics SET unit = ? WHERE id = ?",
-                (unit, metric_id),
-            )
         self.conn.commit()
 
     def delete_metric_bound(self, domain_id: int, metric_id: int) -> None: