Add schema for agent personas, parts, traits, and character arcs

- Created tables for agent_personas, agent_parts, agent_traits, and character_arcs.
- Established relationships between personas, parts, skills, guardrails, and traits.
- Added arc stages and their corresponding parts, along with a persona_arc table to track current stages.
- Implemented cascading delete rules for referential integrity.

schema/agent_personas.dbml

@@ -0,0 +1,132 @@
+Table agent_personas {
+  id bigserial [pk]
+  guid uuid [unique, not null, default: `gen_random_uuid()`]
+  name text [unique, not null]
+  description text [not null, default: '']
+  summary text [not null]
+  detail text [not null, default: '']
+  compiled_summary text [not null, default: '']
+  compiled_detail text [not null, default: '']
+  compiled_at timestamptz
+  tags "text[]" [not null, default: `'{}'`]
+  created_at timestamptz [not null, default: `now()`]
+  updated_at timestamptz [not null, default: `now()`]
+}
+
+Table agent_parts {
+  id bigserial [pk]
+  guid uuid [unique, not null, default: `gen_random_uuid()`]
+  name text [unique, not null]
+  part_type text [not null]
+  description text [not null, default: '']
+  summary text [not null]
+  content text [not null, default: '']
+  tags "text[]" [not null, default: `'{}'`]
+  created_at timestamptz [not null, default: `now()`]
+  updated_at timestamptz [not null, default: `now()`]
+}
+
+Table agent_persona_parts {
+  persona_id bigint [not null, ref: > agent_personas.id]
+  part_id bigint [not null, ref: > agent_parts.id]
+  part_order int [not null, default: 0]
+  priority int [not null, default: 0]
+
+  indexes {
+    (persona_id, part_id) [pk]
+    persona_id
+  }
+}
+
+Table agent_persona_skills {
+  persona_id bigint [not null, ref: > agent_personas.id]
+  skill_id bigint [not null, ref: > agent_skills.id]
+
+  indexes {
+    (persona_id, skill_id) [pk]
+    persona_id
+  }
+}
+
+Table agent_persona_guardrails {
+  persona_id bigint [not null, ref: > agent_personas.id]
+  guardrail_id bigint [not null, ref: > agent_guardrails.id]
+
+  indexes {
+    (persona_id, guardrail_id) [pk]
+    persona_id
+  }
+}
+
+Table agent_traits {
+  id bigserial [pk]
+  guid uuid [unique, not null, default: `gen_random_uuid()`]
+  name text [unique, not null]
+  trait_type text [not null]
+  description text [not null, default: '']
+  instruction text [not null, default: '']
+  tags "text[]" [not null, default: `'{}'`]
+  created_at timestamptz [not null, default: `now()`]
+  updated_at timestamptz [not null, default: `now()`]
+}
+
+Table agent_persona_traits {
+  persona_id bigint [not null, ref: > agent_personas.id]
+  trait_id bigint [not null, ref: > agent_traits.id]
+
+  indexes {
+    (persona_id, trait_id) [pk]
+    persona_id
+  }
+}
+
+Table character_arcs {
+  id bigserial [pk]
+  name text [unique, not null]
+  description text [not null, default: '']
+  summary text [not null, default: '']
+  created_at timestamptz [not null, default: `now()`]
+  updated_at timestamptz [not null, default: `now()`]
+}
+
+Table arc_stages {
+  id bigserial [pk]
+  arc_id bigint [not null, ref: > character_arcs.id]
+  name text [not null]
+  stage_order int [not null, default: 0]
+  description text [not null, default: '']
+  condition text [not null, default: '']
+  created_at timestamptz [not null, default: `now()`]
+}
+
+Table arc_stage_parts {
+  stage_id bigint [not null, ref: > arc_stages.id]
+  part_id bigint [not null, ref: > agent_parts.id]
+
+  indexes {
+    (stage_id, part_id) [pk]
+  }
+}
+
+Table persona_arc {
+  persona_id bigint [pk, ref: > agent_personas.id]
+  arc_id bigint [not null, ref: > character_arcs.id]
+  current_stage_id bigint [not null, ref: > arc_stages.id]
+  updated_at timestamptz [not null, default: `now()`]
+}
+
+// Cross-file refs (for relspecgo merge)
+Ref: agent_persona_parts.persona_id > agent_personas.id [delete: cascade]
+Ref: agent_persona_parts.part_id > agent_parts.id [delete: cascade]
+Ref: agent_persona_skills.persona_id > agent_personas.id [delete: cascade]
+Ref: agent_persona_skills.skill_id > agent_skills.id [delete: cascade]
+Ref: agent_persona_guardrails.persona_id > agent_personas.id [delete: cascade]
+Ref: agent_persona_guardrails.guardrail_id > agent_guardrails.id [delete: cascade]
+Ref: agent_persona_traits.persona_id > agent_personas.id [delete: cascade]
+Ref: agent_persona_traits.trait_id > agent_traits.id [delete: cascade]
+Ref: arc_stages.arc_id > character_arcs.id [delete: cascade]
+Ref: arc_stage_parts.stage_id > arc_stages.id [delete: cascade]
+Ref: arc_stage_parts.part_id > agent_parts.id [delete: cascade]
+Ref: persona_arc.persona_id > agent_personas.id [delete: cascade]
+Ref: persona_arc.arc_id > character_arcs.id
+Ref: persona_arc.current_stage_id > arc_stages.id