feat: model PostgreSQL temporal key and foreign key constraints

[minleejae]

PostgreSQL 18 adds temporal PRIMARY KEY/UNIQUE constraints with WITHOUT OVERLAPS and foreign keys with PERIOD. These forms currently fail to parse, preventing schema tools from reading temporal table definitions.

Add explicit temporal markers to index-column metadata and the foreign-key reference model. PRIMARY KEY and UNIQUE share the existing index-key parser; both sides of a foreign key share a column-list parser that enforces the final-column position of PERIOD. CREATE TABLE and ALTER TABLE ADD reuse these paths. The legacy referenced-column-name list keeps bare names and remains mutable.

Execution comparison also exposed a related ALTER UNIQUE bug: named PostgreSQL constraints lost their names on output. Reusing NamedConstraint preserves the name for both ordinary and temporal UNIQUE constraints.

Validation:

• Full Gradle check with Java 17, including grammar ambiguity and static analysis.
• AST/mutation and round-trip tests cover PRIMARY KEY, UNIQUE/NULLS NOT DISTINCT, INCLUDE/deferrability, explicit/omitted referenced columns, quoted identifiers, ordinary period identifiers, statement boundaries, and malformed marker placement.
• Twelve PostgreSQL 18.6 execution cases compare original, toString(), and deparser SQL, including constraint names and temporal catalog flags. Behavior checks verify overlap rejection and a child range covered jointly by adjacent parent ranges.
• Six referential-action combinations rejected by PostgreSQL 18.6 are recorded as semantic boundaries. The parser represents the syntax; it does not validate range types, operator classes, or all server-specific action restrictions.

Use Dialect.POSTGRESQL for the PostgreSQL ALTER constraint paths. Reference: PostgreSQL 18 CREATE TABLE.

[manticore-projects]

Please resolve conflicts

[manticore-projects]

Thank you!