refactor: Unify agent_turn_context and agent_bootstrap_context schema

[NOVA-Openclaw]

Background

The two context tables (agent_turn_context and agent_bootstrap_context) evolved separately and have inconsistent column naming and constraints. This creates confusion and maintenance overhead.

Current state

agent_turn_context:

• context_type (UNIVERSAL/GLOBAL/DOMAIN/AGENT)
• context_key — scope identifier (domain name, agent name, or *)
• document_name — redundant with context_key since there's only one row per scope
• Unique: (context_type, document_name)

agent_bootstrap_context:

• context_type (UNIVERSAL/GLOBAL/DOMAIN/AGENT)
• domain_name — set for DOMAIN type
• agent_name — set for AGENT type
• document_name — distinguishes multiple documents within a scope
• Unique: (context_type, COALESCE(agent_name, ''), COALESCE(domain_name, ''), document_name)

Problems

1. context_key vs domain_name/agent_name — same concept, different names
2. document_name is redundant in turn context (one row per scope)
3. No enforcement that UNIVERSAL and GLOBAL have only one row each
4. COALESCE in unique index is ugly — separate columns for the same logical field

Changes

1. agent_turn_context

• Drop document_name column
• Rename context_key → context_name
• New unique constraint: (context_type, context_name)
• context_name values: '*' for UNIVERSAL/GLOBAL, domain name for DOMAIN, agent name for AGENT

2. agent_bootstrap_context

• Drop domain_name and agent_name columns
• Add context_name column (replaces both)
• Keep document_name (bootstrap has multiple documents per scope)
• New unique constraint: (context_type, context_name, document_name)
• context_name values: '*' for UNIVERSAL/GLOBAL, domain name for DOMAIN, agent name for AGENT

3. Shared pattern

Both tables use context_type + context_name as the scope identifier. Bootstrap adds document_name as a third dimension for multiple documents per scope.

4. Enforce UNIVERSAL/GLOBAL uniqueness

• agent_turn_context: Add partial unique index — only ONE row where context_type = 'UNIVERSAL', only ONE row where context_type = 'GLOBAL'
• agent_bootstrap_context: UNIVERSAL/GLOBAL can have multiple rows (multiple documents), but all share context_name = '*'. Uniqueness is already handled by (context_type, context_name, document_name)

5. Update dependent code

• get_agent_turn_context() function — query uses context_name instead of context_key
• get_agent_bootstrap() function — query uses context_name instead of domain_name/agent_name
• protect_bootstrap_context_writes() trigger — references column names
• agent-turn-context hook (handler.ts) — if it references column names
• db-bootstrap-context hook (handler.ts) — column name references
• Logical replication publications (graybeard_sync_pub) — WHERE clauses reference column names
• Any CHECK constraints referencing old column names

Migration strategy

• Pre-migration script to populate context_name from existing domain_name/agent_name/context_key
• Then pgschema handles the structural diff
• Backward-compatible: existing data preserved, just column renames

Constraints

• One UNIVERSAL row in agent_turn_context, one GLOBAL row
• One DOMAIN row per domain name in agent_turn_context
• One AGENT row per agent name in agent_turn_context
• Bootstrap allows multiple rows per scope (distinguished by document_name)