feat: unified Agent/Citizen model with visibility controls

- Add visibility_scope, is_listed_in_directory, is_system, primary_microdao_id to agents
- Create unified list_agent_summaries method
- Add PUT /city/agents/{id}/visibility endpoint
- Add AgentVisibilityCard component
- Update AgentSummary types for frontend

migrations/024_agent_visibility_fields.sql

@@ -0,0 +1,77 @@
+-- Migration: Add visibility and listing fields to agents
+-- Purpose: Unify Agent/Citizen model with proper visibility control
+-- Date: 2025-11-28
+
+-- Add visibility scope field
+ALTER TABLE agents
+    ADD COLUMN IF NOT EXISTS visibility_scope TEXT NOT NULL DEFAULT 'city';
+
+-- Add listing in directory flag
+ALTER TABLE agents
+    ADD COLUMN IF NOT EXISTS is_listed_in_directory BOOLEAN NOT NULL DEFAULT true;
+
+-- Add system agent flag
+ALTER TABLE agents
+    ADD COLUMN IF NOT EXISTS is_system BOOLEAN NOT NULL DEFAULT false;
+
+-- Add primary microDAO reference
+ALTER TABLE agents
+    ADD COLUMN IF NOT EXISTS primary_microdao_id TEXT NULL;
+
+-- Add slug for public URL
+ALTER TABLE agents
+    ADD COLUMN IF NOT EXISTS slug TEXT NULL;
+
+-- Create unique index on slug
+CREATE UNIQUE INDEX IF NOT EXISTS idx_agents_slug ON agents(slug) WHERE slug IS NOT NULL;
+
+-- Add check constraint for visibility_scope
+ALTER TABLE agents
+    DROP CONSTRAINT IF EXISTS chk_visibility_scope;
+ALTER TABLE agents
+    ADD CONSTRAINT chk_visibility_scope 
+    CHECK (visibility_scope IN ('city', 'microdao', 'owner_only'));
+
+-- Create index for faster filtering
+CREATE INDEX IF NOT EXISTS idx_agents_visibility ON agents(visibility_scope, is_listed_in_directory);
+CREATE INDEX IF NOT EXISTS idx_agents_primary_microdao ON agents(primary_microdao_id);
+
+-- Update existing public agents to be listed
+UPDATE agents 
+SET is_listed_in_directory = true 
+WHERE is_public = true;
+
+-- Update non-public agents to not be listed
+UPDATE agents 
+SET is_listed_in_directory = false 
+WHERE is_public = false;
+
+-- Set system agents (infrastructure agents)
+UPDATE agents
+SET is_system = true
+WHERE kind IN ('system', 'monitor', 'infrastructure')
+   OR id LIKE 'ag_%';
+
+-- Generate slugs from public_slug or id
+UPDATE agents
+SET slug = COALESCE(public_slug, LOWER(REPLACE(display_name, ' ', '-')))
+WHERE slug IS NULL;
+
+-- Set primary_microdao_id from first membership
+UPDATE agents a
+SET primary_microdao_id = (
+    SELECT ma.microdao_id 
+    FROM microdao_agents ma 
+    WHERE ma.agent_id = a.id 
+    ORDER BY ma.created_at 
+    LIMIT 1
+)
+WHERE primary_microdao_id IS NULL;
+
+-- Comments
+COMMENT ON COLUMN agents.visibility_scope IS 'Visibility: city (public), microdao (members only), owner_only (private)';
+COMMENT ON COLUMN agents.is_listed_in_directory IS 'Show in public Citizens directory';
+COMMENT ON COLUMN agents.is_system IS 'System/infrastructure agent';
+COMMENT ON COLUMN agents.primary_microdao_id IS 'Primary MicroDAO for this agent';
+COMMENT ON COLUMN agents.slug IS 'URL-friendly slug for agent profile';
+