docs(docs): file D-096–D-109 and Q-045–Q-050 from generator workshop

14 confirmed decisions filed across architecture.md (10) and content.md (4).
6 open questions filed in questions.md (Q-046 resolved immediately by D-108).
README.md index updated.

Key decisions: DistrictLayoutMode (D-096), guarantee tier system (D-097),
MobileChunk spec (D-108), DamageOverlay prohibition (D-109), WorldTier
enum with corrected constraint ceilings, heritage grammar overlay (D-104).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

decisions/content.md

@@ -249,4 +249,42 @@ How narrative, NPCs, and world content are created: content tiers, NPC generatio
 
 ---
 
-*21 decisions. Last updated: 2026-02-25 (D-093, D-095 added — Station District Layout Workshop, Sprint 20)*
+### D-098: TrianglePurpose Enum
+- **Date:** 2026-02-27
+- **Decision:** Social triangles carry `Vec<TrianglePurpose>` — a multi-tag set for playstyle accessibility. Enum values: `Investigation, Economic, Social, Political, Tactical, Mundane`. `Tactical` encodes the assassination contract in spatial form (target + protector + informant/witness). Multiple purpose tags per triangle: a smuggling operation can be `Economic + Tactical` simultaneously. Purpose tags ensure the right drama is surfaced to the player whose active lens matches — they add no generation cost, categorizing existing output.
+- **Rationale:** Purpose tags are the bridge between the generator's social structure and the player's active playstyle. The generator doesn't build for one playstyle — it tags what's already there.
+- **Source:** Generator Architecture Workshop (#562), 2026-02-27. `docs/workshops/generator-architecture/workshop-outcomes.md` §D-READY-3.
+- **Raised by:** Gestalt (triangle purpose model). Full team sign-off.
+- **Dissent:** None.
+- **Cross-reference:** D-025 (social site / functional cluster — triangles populate social sites), D-097 (guarantee tier system — triangles feed the audit)
+
+### D-104: Heritage Grammar Overlay for Non-Urban Palettes
+- **Date:** 2026-02-27
+- **Decision:** Data-driven `HeritageGrammarOverlay` structs (10 per heritage root). Loaded once at generator startup, applied at Phase 2 chunk fill by weighted blending. Blend rules: continuous fields (decorative_density, repair_visibility, etc.) use weighted average; categorical fields (boundary_character, open_space_character) use dominant heritage weight; object tag lists use union of preferred/accent tags and intersection-exclusion of excluded tags. Phase 1 exception: `gathering_probability` evaluated at block planning for quarter pre-assignment. Authoring domain separation: **Miri** authors organizational principles, boundary character, spacing, social grammar (HeritageGrammarOverlay Rust struct / authored data). **Araminta** authors visual expression — object sets, arrangement algorithms, floor surface variants, overhead flora density and character, wall/structure material character, boundary material type, lighting temperature (TOML modifier files, one per heritage root). Shared: `ObjectTag` vocabulary must be co-maintained (see Q-049).
+- **Rationale:** Heritage roots must be spatially legible — the visual grammar of a Frost community versus a Tide community must be apparent to the observant player without a label.
+- **Source:** Generator Architecture Workshop (#562), 2026-02-27. `docs/workshops/generator-architecture/workshop-outcomes.md` §D-READY-9.
+- **Raised by:** Miri (cultural grammar spec), Araminta (TOML modifier design and authoring domain). Full team sign-off.
+- **Dissent:** None.
+- **Cross-reference:** D-101 (ZonePalette — heritage modifier axis A), D-105 (informal zone typology — heritage correlations), Q-049 (ObjectTag co-maintenance)
+
+### D-105: Non-Urban Informal Zone Typology
+- **Date:** 2026-02-27
+- **Decision:** Informal zones (spaces outside the community's social field) are defined by the type of social permission governing them, not by institutional absence. Three types: `physical_distance` — sparse objects, unmaintained floor; isolation is the visual. `social_permission` — normal zone palette; gathering infrastructure present; cover is about convention, not geography. `utilitarian_cover` — functional work objects; space reads as work space; unofficial use invisible to casual observation. Heritage root correlations: Frost/Stone → `physical_distance`; Tide/Vine/Dust → `social_permission`; Iron/Salt → `utilitarian_cover`. (Dust = maximum communal observation, privacy is negotiated not physical; Iron = labor function covers presence.) Location within terrain seeded independently. Visual grammar per type: `docs/workshops/generator-architecture/araminta-round4.md`.
+- **Rationale:** Privacy mechanics emerge from community culture. How you hide in a Frost community (physical distance) is architecturally different from how you hide in a Dust community (social agreement). The typology makes privacy mechanics culturally legible.
+- **Source:** Generator Architecture Workshop (#562), 2026-02-27. `docs/workshops/generator-architecture/workshop-outcomes.md` §D-READY-10.
+- **Raised by:** Miri (heritage root correlations, canonical mapping corrected Round 5), Araminta (visual grammar per type). Full team sign-off.
+- **Dissent:** None.
+- **Cross-reference:** D-104 (heritage grammar overlay)
+
+### D-107: Trauma Events as EraModification Subtypes
+- **Date:** 2026-02-27
+- **Decision:** Trauma events are a subtype of `EraModification` with dual-track effects. Five subtypes: `PhysicalDestruction, EconomicDisruption, PoliticalShock, ViolenceEvent, MigrationShock`. Separate tracks: (1) structural damage via `StructuralChange` in ChunkMutations (applied as `LocalOverlay` per D-109); (2) cultural response via NPC weight distribution shift in `DistrictRuntimeState.npc_pattern_weights`. Decay rate seeded per-community with variation around heritage-root baseline (`trauma_visual_decay_rate: slow | medium | fast`, default medium). Design principle: **Trauma intensifies culture, it does not transform it.** A stressed community becomes a more concentrated version of itself — Frost communities close harder, Tide communities grief more publicly, Iron communities organize more collectively. Decay is toward the community's pre-trauma baseline, not toward a new equilibrium. Players who have learned a heritage root's trust model can predict community behavior in the aftermath.
+- **Rationale:** Cultural response must be legible — and predictable to a player who has invested in understanding the heritage root. Trauma as amplifier (not transformer) rewards prior observation.
+- **Source:** Generator Architecture Workshop (#562), 2026-02-27. `docs/workshops/generator-architecture/workshop-outcomes.md` §D-READY-12.
+- **Raised by:** Miri (trauma subtypes and heritage decay model, "trauma intensifies culture" principle added Round 5), Tyre (struct design and decay architecture). Full team sign-off.
+- **Dissent:** None.
+- **Cross-reference:** D-100 (DamageOverlay — structural track), D-104 (heritage grammar — cultural baseline), D-109 (LocalOverlay mandate)
+
+---
+
+*25 decisions. Last updated: 2026-02-27 (D-098, D-104, D-105, D-107 added — Generator Architecture Workshop #562)*