feat(events): Phase 3 — AI tools, Event-Scout template, feedback loop

- Add discover_events (auto) and suggest_event (propose) to shared-ai
  tool catalog. discover_events reads the discovery feed, suggest_event
  creates a proposal to save a discovered event to the user's calendar.
- Add Event-Scout agent template with daily "Events der Woche" mission.
  Policy: discover_events=auto, suggest_event=propose, all else denied.
- Add frontend tool implementations in events/tools.ts — discover_events
  calls the feed API, suggest_event delegates to discoveryStore.saveEvent.
- Add feedback.ts — computes implicit user profile from save/dismiss
  history (category affinity + source quality as 0–2x weight multipliers).

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

services/mana-events/src/discovery/feedback.ts

@@ -0,0 +1,128 @@
+/**
+ * Feedback loop — aggregate save/dismiss ratios per category and source
+ * to build an implicit user profile for better relevance scoring.
+ *
+ * The profile is computed on-demand from discovery_user_actions joined
+ * with discovered_events. No separate table needed — the action history
+ * IS the profile.
+ */
+
+import { eq, sql } from 'drizzle-orm';
+import type { Database } from '../db/connection';
+import { discoveryUserActions, discoveredEvents } from '../db/schema/discovery';
+
+/** Per-category affinity based on save/dismiss ratio. */
+export interface CategoryAffinity {
+	category: string;
+	saves: number;
+	dismisses: number;
+	/** 0.0–2.0 multiplier: >1 means user likes this category, <1 means dislikes. */
+	weight: number;
+}
+
+/** Per-source quality based on save/dismiss ratio. */
+export interface SourceQuality {
+	sourceId: string;
+	sourceName: string | null;
+	saves: number;
+	dismisses: number;
+	/** 0.0–2.0 multiplier. Sources with high dismiss rate get penalized. */
+	weight: number;
+}
+
+export interface UserProfile {
+	categoryAffinities: CategoryAffinity[];
+	sourceQualities: SourceQuality[];
+	totalActions: number;
+}
+
+/**
+ * Compute an implicit user profile from their save/dismiss history.
+ * Returns category affinities and source quality metrics.
+ *
+ * Requires at least 5 actions to be meaningful — returns empty profile
+ * if insufficient data.
+ */
+export async function computeUserProfile(db: Database, userId: string): Promise<UserProfile> {
+	// Count total actions to check if we have enough data
+	const countResult = await db
+		.select({ count: sql<number>`count(*)::int` })
+		.from(discoveryUserActions)
+		.where(eq(discoveryUserActions.userId, userId));
+
+	const totalActions = countResult[0]?.count ?? 0;
+	if (totalActions < 5) {
+		return { categoryAffinities: [], sourceQualities: [], totalActions };
+	}
+
+	// Category affinities: group by category, count saves/dismisses
+	const categoryRows = await db.execute(sql`
+		SELECT
+			de.category,
+			COUNT(*) FILTER (WHERE dua.action = 'save') AS saves,
+			COUNT(*) FILTER (WHERE dua.action = 'dismiss') AS dismisses
+		FROM event_discovery.discovery_user_actions dua
+		JOIN event_discovery.discovered_events de ON de.id = dua.event_id
+		WHERE dua.user_id = ${userId} AND de.category IS NOT NULL
+		GROUP BY de.category
+		ORDER BY saves DESC
+	`);
+
+	const categoryAffinities: CategoryAffinity[] = (
+		categoryRows as unknown as Array<{
+			category: string;
+			saves: string;
+			dismisses: string;
+		}>
+	).map((row) => {
+		const saves = parseInt(row.saves, 10);
+		const dismisses = parseInt(row.dismisses, 10);
+		const total = saves + dismisses;
+		// Weight: ratio of saves to total, scaled to 0–2 range
+		// 100% saves → 2.0, 50% → 1.0, 0% → 0.2 (floor)
+		const ratio = total > 0 ? saves / total : 0.5;
+		return {
+			category: row.category,
+			saves,
+			dismisses,
+			weight: Math.max(0.2, ratio * 2),
+		};
+	});
+
+	// Source quality: group by source, count saves/dismisses
+	const sourceRows = await db.execute(sql`
+		SELECT
+			de.source_id,
+			de.source_name,
+			COUNT(*) FILTER (WHERE dua.action = 'save') AS saves,
+			COUNT(*) FILTER (WHERE dua.action = 'dismiss') AS dismisses
+		FROM event_discovery.discovery_user_actions dua
+		JOIN event_discovery.discovered_events de ON de.id = dua.event_id
+		WHERE dua.user_id = ${userId}
+		GROUP BY de.source_id, de.source_name
+		ORDER BY saves DESC
+	`);
+
+	const sourceQualities: SourceQuality[] = (
+		sourceRows as unknown as Array<{
+			source_id: string;
+			source_name: string | null;
+			saves: string;
+			dismisses: string;
+		}>
+	).map((row) => {
+		const saves = parseInt(row.saves, 10);
+		const dismisses = parseInt(row.dismisses, 10);
+		const total = saves + dismisses;
+		const ratio = total > 0 ? saves / total : 0.5;
+		return {
+			sourceId: row.source_id,
+			sourceName: row.source_name,
+			saves,
+			dismisses,
+			weight: Math.max(0.2, ratio * 2),
+		};
+	});
+
+	return { categoryAffinities, sourceQualities, totalActions };
+}