feat(db): add project personas and skills tables

* Introduce project_personas table with foreign keys to projects and agent_personas
* Add project_skills table with foreign key to projects and agent_skills
* Include override boolean field in agent_persona_skills and project_skills
* Update schema and migration files to reflect new tables and fields
* Enhance CORS handling to reflect request origin

internal/store/agent_personas.go

@@ -234,6 +234,7 @@ func (db *DB) GetPersona(ctx context.Context, name string, detail bool, override
 			Name:        s.Name,
 			Description: s.Description,
 			Tags:        s.Tags,
+			Override:    s.Override,
 		}
 		if detail {
 			entry.Content = s.Content
@@ -341,6 +342,7 @@ func (db *DB) GetPersonaManifest(ctx context.Context, name string) (ext.PersonaM
 			ID:          s.ID,
 			Name:        s.Name,
 			Description: s.Description,
+			Override:    s.Override,
 		})
 	}
 	for _, g := range guardrails {
@@ -567,11 +569,12 @@ func (db *DB) RemovePersonaPart(ctx context.Context, personaName, partName strin
 // Persona-Skill links
 // ──────────────────────────────────────────────
 
-func (db *DB) AddPersonaSkill(ctx context.Context, personaID, skillID int64) error {
+func (db *DB) AddPersonaSkill(ctx context.Context, personaID, skillID int64, override bool) error {
 	_, err := db.pool.Exec(ctx, `
-		insert into agent_persona_skills (persona_id, skill_id)
-		values ($1, $2) on conflict do nothing
-	`, personaID, skillID)
+		insert into agent_persona_skills (persona_id, skill_id, override)
+		values ($1, $2, $3)
+		on conflict (persona_id, skill_id) do update set override = excluded.override
+	`, personaID, skillID, override)
 	if err != nil {
 		return fmt.Errorf("add persona skill: %w", err)
 	}
@@ -1058,7 +1061,7 @@ func (db *DB) fetchPartsByNames(ctx context.Context, names []string) ([]rawPart,
 
 func (db *DB) listPersonaSkills(ctx context.Context, personaID int64) ([]AgentSkillRow, error) {
 	rows, err := db.pool.Query(ctx, `
-		select s.id, s.name, s.description, s.content, s.tags::text[]
+		select s.id, s.name, s.description, s.content, s.tags::text[], aps.override
 		from agent_skills s
 		join agent_persona_skills aps on aps.skill_id = s.id
 		where aps.persona_id = $1
@@ -1073,7 +1076,7 @@ func (db *DB) listPersonaSkills(ctx context.Context, personaID int64) ([]AgentSk
 	for rows.Next() {
 		var s AgentSkillRow
 		var tags []string
-		if err := rows.Scan(&s.ID, &s.Name, &s.Description, &s.Content, &tags); err != nil {
+		if err := rows.Scan(&s.ID, &s.Name, &s.Description, &s.Content, &tags, &s.Override); err != nil {
 			return nil, fmt.Errorf("scan persona skill: %w", err)
 		}
 		s.Tags = nilToEmptyStrings(tags)
@@ -1139,6 +1142,7 @@ type AgentSkillRow struct {
 	Description string
 	Content     string
 	Tags        []string
+	Override    bool
 }
 
 type AgentGuardrailRow struct {