feat: procedure mode

[tianzhou]

Fix #65

[Copilot]

Pull Request Overview

This PR implements procedure mode support to enhance PostgreSQL procedure parameter handling. The changes ensure that procedure parameters include explicit mode specifications (IN, OUT, INOUT) in both creation and drop statements, matching pg_dump behavior for better PostgreSQL compatibility.

• Adds explicit parameter mode handling in procedure parsing and generation
• Updates DROP PROCEDURE statements to include full parameter signatures with modes and names
• Adds structured parameter support with new Signature and Parameters fields

Reviewed Changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
testdata/dump/employee/pgschema.sql	Updates procedure definition to include explicit IN mode for parameters
testdata/diff/migrate/v5/*	Updates DROP PROCEDURE statements to use full parameter signatures instead of type-only
testdata/diff/create_procedure/*	Updates test cases to use explicit parameter modes and full signatures
ir/parser.go	Adds signature generation with explicit parameter modes and structured parameter support
ir/inspector.go	Enhances parameter parsing to handle mode keywords (IN, OUT, INOUT, etc.)
internal/diff/procedure.go	Replaces type-only parameter extraction with full signature formatting for DROP statements

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[Copilot]

The comment on line 1877 contradicts the implementation. The comment states 'Only include non-default modes explicitly' but the code always includes 'IN' mode explicitly in the else branch, which contradicts the 'only' statement.