feat(simulation): Layer-3 settlement spatial-character enrichment (#956)

Derive and store each placed settlement's spatial character on top of the
#955 placement (D-212/213/214/215). Derivation is pure + integer-deterministic
(D-010); the cascade stays DB-free (D-225) — the enqueuer pre-resolves the
body's system faction onto the work item, like #955's settlements.

- TerritorialStatus (D-212): mapped from the authored dominant_faction
  (territorial_status_from_faction). Adds an AutonomistHeld variant for the
  Compact of Westphalia (self-governing bloc that rejects Assembly authority —
  neither Commission, Corp, Contested, nor truly Frontier). Grounded in
  wiki/factions/. Stored per-province on DrainageBasin.territorial_status
  (uniform per body for now; forward-compatible for per-province faction data).
- PoliticalArchetype (D-214): political_archetype(status, role), status takes
  precedence over economic_role.
- ArrangementPattern (D-215): new 5-variant enum + arrangement_pattern(); the
  block-adjacency *enforcement* stays deferred to the Quarter-skeleton gen (#957)
  — this only derives + stores which pattern applies.
- FoundingOrientation (D-213): existing fn extended with a seed-derived Free
  bearing so pioneer/open-terrain grids vary per seed.

Wiring: dominant_faction threaded through CityContextReader
(read_body_dominant_faction) → atlas proxy (cache-miss read) → AnalyzeBody work
item → run_cascade → run_layer3/match_cities. Enrichment stored on CityPlacement
(political_archetype, arrangement_pattern, founding_orientation).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/src/simulation/generator.rs

@@ -365,23 +365,56 @@ pub enum FoundingOrientation {
 }
 
 /// Territory control status for a province (drainage basin). Priority-ordered derivation.
-/// Source: D-212
+/// Source: D-212 (amended 2026-06-05 — see `AutonomistHeld` + the dominant_faction
+/// mapping note on the variant docs and in `attractor_matching::territorial_status_from_faction`).
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq)]
 pub enum TerritorialStatus {
-    /// Commission faction_influence ≥ 0.6 in this province.
+    /// Established central governance — the Concord Assembly or its aligned
+    /// institutions (e.g. the Veil Institute). (Original D-212: Commission
+    /// faction_influence ≥ 0.6.)
     CommissionControlled,
-    /// Single corporation faction_influence ≥ 0.5.
+    /// Commercial control — Syndic combines. (Original D-212: single corporation
+    /// faction_influence ≥ 0.5.)
     CorpTerritory,
     /// Two or more factions each ≥ 0.3; no dominant faction.
     ContestedZone,
     /// No faction with influence ≥ 0.2.
     FrontierUnclaimed,
+    /// Self-governing autonomist bloc that rejects central (Assembly) authority —
+    /// the Compact of Westphalia and compact-sympathetic systems. Locally
+    /// governed, but outside the Assembly's reach (D-212 amendment 2026-06-05).
+    AutonomistHeld,
     /// Cultural corridor has indigenous autonomy flag.
     IndigenousHeld,
     /// Population density < 0.01 AND no faction ≥ 0.1.
     Derelict,
 }
 
+/// Spatial arrangement pattern governing district adjacency and landmark
+/// placement within a settlement (D-215). Derived from `PoliticalArchetype`
+/// (+ transit_hub economic role → `HubAndSpoke`). #956 derives and stores which
+/// pattern applies; the block-adjacency *enforcement* is the Quarter-skeleton
+/// generator's job (#957).
+/// Source: D-215
+#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ArrangementPattern {
+    /// Central landmark surrounded by mixed-use rings, transit spokes radiating
+    /// outward (Commission, Academic).
+    RadialCore,
+    /// Restricted campus block in the interior, commercial ring, peripheral
+    /// worker residential (Corporate).
+    CampusGrid,
+    /// Districts string along a linear feature; no dominant center (Pioneer,
+    /// Industrial).
+    RibbonDevelopment,
+    /// Restricted/secured districts at the footprint edge, open interior core,
+    /// single controlled access per edge (Military).
+    FortifiedPerimeter,
+    /// Transit district at center, all others reachable via direct corridors
+    /// (transit_hub economic role, any archetype).
+    HubAndSpoke,
+}
+
 // ---------------------------------------------------------------------------
 // Attractor types for settlement placement (D-195, D-209, D-211)
 // ---------------------------------------------------------------------------