replace stub estimator with a requirement-derived physics engine

pass 2's no-LLM fallback previously used broken/placeholder formulas:
power_density passed an actuator's own intensive W/kg straight through
without scaling by vehicle mass, range_fuel multiplied energy_density by a
flat unitless constant, and cost_efficiency was a categorical guess.

Replaces all three with formulas grounded in each entity's own declared
attributes. Actuator and storage mass are sized to what's actually
necessary -- enough power to sustain a platform's target_velocity against
resistance (or real thrust/accel requirements where already declared, for
aircraft/rocket combos), enough energy to reach the domain's own declared
range ceiling -- solved as a closed-form 2x2 linear system rather than an
invented mass-fraction table. Platform mass uses the geometric mean of its
declared range instead of the bare floor, since a category as broad as
Road Vehicle (50kg-36,000kg) is closer to log-uniformly distributed than
uniformly distributed. cost_efficiency is now real operating cost (energy
price x resistance) plus amortized upfront cost (materials cost by medium
x lifetime distance), replacing the old flat per-energy-form guess.

Also fixes two bugs found while validating the above against real-world
reference values: entities whose power source isn't their own carried mass
(Human Muscle, Solar Sail) degenerated to zero power; and combos blocked
by a domain-specific constraint kept combinations.status stuck at "valid"
forever, which silently miscounted them as passing in two repository
queries (count_combinations_by_status, get_pipeline_summary) even though
the per-domain result row was correctly marked blocked.

Adds target_velocity to platforms that had no declared performance
requirement at all, and raises OllamaLLMProvider's HTTP timeout (120s to
300s) to match observed real review-call latency.

Validated against 4 real-world reference combos (commuter car, bicycle,
delivery drone) and a full 2,970-combination domain run (0 pass-2
failures); all 100 existing tests still pass.

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

src/physcom/llm/providers/ollama.py

@@ -54,7 +54,7 @@ class OllamaLLMProvider(LLMProvider):
             headers={"Content-Type": "application/json"},
         )
         try:
-            with urllib.request.urlopen(req, timeout=120) as resp:
+            with urllib.request.urlopen(req, timeout=300) as resp:
                 return json.loads(resp.read())["response"]
         except urllib.error.URLError as exc:
             raise ConnectionError(