fix(simulation): address PR #122 review — determinism, correctness, labeling

- HashMap → BTreeMap throughout econ-sim for deterministic iteration (D-010)
- Fix cost_factor: multiplicative gate×zone instead of additive (trade.rs)
- Extract derive_seed to shared prng.rs, consolidate FNV-1a implementation
- Rename run_shock_test → run_no_explosion_check (not D-179 Test 3)
- Deduplicate cross-zone FX rate collection in Test 4
- Replace ORDER BY RANDOM() with deterministic ordering + ChaCha8Rng
- Make commodity coverage failure a hard error consistent with D-175
- Fix gap-fill off-by-one (4 corps → 3 when coverage = 0)
- Correct test report: EconEvent exists, location_type is body/station

All four D-179 stability tests still pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tooling/econ-sim/src/agents.rs

@@ -16,7 +16,7 @@
 //! Trade-layer archetype effects (corp-level bid/ask) are deferred to a
 //! future sprint when the event port (D-180) and IPC bridge are in place.
 
-use std::collections::HashMap;
+use std::collections::BTreeMap;
 
 // ---------------------------------------------------------------------------
 // EconEvent — D-180 event port stub (#809)
@@ -49,8 +49,8 @@ pub enum EventEffect {
 #[allow(dead_code)]
 pub enum EventVisibility {
     Global,
-    Proximate(u32),           // hops
-    Disclosed(Vec<String>),   // specific node IDs
+    Proximate(u32),         // hops
+    Disclosed(Vec<String>), // specific node IDs
     Hidden,
 }
 
@@ -107,13 +107,27 @@ impl Archetype {
     /// Falls back to `Producer` (the most neutral, maximises output).
     pub fn infer_from_specialization(spec: &str) -> Self {
         let s = spec.to_lowercase();
-        if s.contains("freight") || s.contains("logistics") || s.contains("hauler") || s.contains("cargo") {
+        if s.contains("freight")
+            || s.contains("logistics")
+            || s.contains("hauler")
+            || s.contains("cargo")
+        {
             Archetype::Distributor
-        } else if s.contains("arbitr") || s.contains("trading company") || s.contains("brokerage") || s.contains("intermediar") {
+        } else if s.contains("arbitr")
+            || s.contains("trading company")
+            || s.contains("brokerage")
+            || s.contains("intermediar")
+        {
             Archetype::Intermediary
         } else if s.contains("cooperative") || s.contains("mutu") || s.contains("negociant") {
             Archetype::Cooperative
-        } else if s.contains("whisky") || s.contains("wine") || s.contains("lager") || s.contains("precision") || s.contains("bespoke") || s.contains("longevity") {
+        } else if s.contains("whisky")
+            || s.contains("wine")
+            || s.contains("lager")
+            || s.contains("precision")
+            || s.contains("bespoke")
+            || s.contains("longevity")
+        {
             Archetype::Specialist
         } else if s.contains("infrastructure") && (s.contains("gate") || s.contains("span")) {
             // Gate Corp maintains infrastructure monopoly
@@ -193,7 +207,7 @@ pub struct ArchetypeParams {
 /// `corp_data`: Vec of (corp_id, behavioral_archetype_opt, specialization_opt)
 pub fn build_archetype_map(
     corp_data: Vec<(String, Option<String>, Option<String>)>,
-) -> HashMap<String, Archetype> {
+) -> BTreeMap<String, Archetype> {
     corp_data
         .into_iter()
         .map(|(corp_id, archetype_str, specialization)| {