feat(who): add character dossier system for staged fact disclosure

Pre-researched dossiers (37 JSON files, DE+EN) replace the old
personality strings as the source of truth for the Who guessing game.
A strong cloud LLM (Gemini 2.5 Flash) generates structured facts per
character — voice, values, achievements, anecdotes, relationships,
forbidden-early-words, and three-stage hints — so the small runtime
model (gemma3:4b) gets only what it needs per turn instead of raw
personality text that leaks the identity immediately.

- dossier-types.ts: Zod schema + TS types for CharacterDossier
- dossier-loader.ts: boot-time loader with validation + coverage report
- generate-who-dossiers.ts: one-shot generator script (Google Gemini
  or local mana-llm fallback, idempotent, --force/--id flags)
- 37 dossier JSON files in data/dossiers/

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

apps/api/src/modules/who/data/dossier-loader.ts

@@ -0,0 +1,97 @@
+/**
+ * Loads character dossiers at boot time.
+ *
+ * Dossiers live as JSON files at ./dossiers/{id}.json — one per character.
+ * They are generated by apps/api/scripts/generate-who-dossiers.ts (a strong
+ * cloud LLM does the research) and then consumed at runtime by the small
+ * model (gemma3:4b) in carefully staged chunks to keep gameplay coherent.
+ *
+ * This loader:
+ *  1. Reads every {id}.json under ./dossiers/
+ *  2. Validates each against CharacterDossierSchema (Zod)
+ *  3. Sanity-checks that the dossier id matches the filename
+ *  4. Builds a Map<id, dossier> for O(1) runtime lookup
+ *
+ * Missing dossiers are NOT a hard error — the prompt builder falls back to
+ * the legacy `personality` string on the WhoCharacter so the module keeps
+ * working during the rollout. We only warn at boot.
+ */
+
+/* eslint-disable no-console */
+import { readdirSync, readFileSync, existsSync } from 'node:fs';
+import { join, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { CharacterDossierSchema, type CharacterDossier } from './dossier-types';
+import { CHARACTERS } from './characters';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const DOSSIER_DIR = join(__dirname, 'dossiers');
+
+let dossierCache: Map<number, CharacterDossier> | null = null;
+
+function loadDossiers(): Map<number, CharacterDossier> {
+	const map = new Map<number, CharacterDossier>();
+
+	if (!existsSync(DOSSIER_DIR)) {
+		console.warn(
+			`[who] dossier directory missing at ${DOSSIER_DIR} — falling back to legacy personality strings for all characters. Run: bun run apps/api/scripts/generate-who-dossiers.ts`
+		);
+		return map;
+	}
+
+	const files = readdirSync(DOSSIER_DIR).filter(
+		(f) => f.endsWith('.json') && !f.endsWith('.raw.json')
+	);
+
+	for (const file of files) {
+		const path = join(DOSSIER_DIR, file);
+		try {
+			const raw = readFileSync(path, 'utf8');
+			const parsed = JSON.parse(raw);
+			const dossier = CharacterDossierSchema.parse(parsed);
+
+			// Filename must match the dossier id (catches accidental copies)
+			const expectedId = Number(file.replace('.json', ''));
+			if (dossier.id !== expectedId) {
+				console.warn(
+					`[who] dossier ${file}: id mismatch (file=${expectedId}, content=${dossier.id}) — skipping`
+				);
+				continue;
+			}
+
+			map.set(dossier.id, dossier);
+		} catch (err) {
+			console.warn(
+				`[who] failed to load dossier ${file}: ${err instanceof Error ? err.message : String(err)}`
+			);
+		}
+	}
+
+	// Report coverage so devs notice gaps quickly during rollout
+	const missing = CHARACTERS.filter((c) => !map.has(c.id));
+	if (missing.length > 0) {
+		console.warn(
+			`[who] ${map.size}/${CHARACTERS.length} dossiers loaded; missing ids: ${missing
+				.map((c) => `${c.id}(${c.name})`)
+				.join(', ')}`
+		);
+	} else {
+		console.log(`[who] loaded ${map.size}/${CHARACTERS.length} character dossiers`);
+	}
+
+	return map;
+}
+
+/** Returns the dossier for a character id, or undefined if not generated yet. */
+export function getDossier(id: number): CharacterDossier | undefined {
+	if (!dossierCache) {
+		dossierCache = loadDossiers();
+	}
+	return dossierCache.get(id);
+}
+
+/** Test/dev helper: force a reload from disk. */
+export function reloadDossiers(): void {
+	dossierCache = null;
+}