Add linter for rename column

[morgo]

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Part of #446

Example output:

mtocker@BLKD5234QXY40 bin % ./spirit diff --source-dsn="spirit:spirit@tcp(127.0.0.1:3306)/source"  --target-alter="alter table t1_old rename column val to val2"
-- [WARNING] rename_column: Column rename detected in table "t1_old": "val" to "val2". Renaming a column cannot be done atomically across application pods, and ORMs that generate column names at compile time (e.g. jOOQ) will break until code is recompiled (Table: t1_old, Column: val) Suggestion: Use ADD COLUMN + DROP COLUMN instead of RENAME COLUMN. This is the only safe approach

alter table t1_old rename column val to val2;

[Copilot]

Pull request overview

Adds a new native lint rule to detect column renames in ALTER TABLE statements, aligning with the broader move toward parser-based linting described in issue #446.

Changes:

• Add rename_column linter to warn on RENAME COLUMN and CHANGE COLUMN old new ... rename patterns.
• Add unit tests covering rename and non-rename ALTER variants.
• Refactor violation sorting/printing helpers into violation.go (and remove the old cmd_common.go), plus ignore bin/ in .gitignore.

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
pkg/lint/lint_rename_column.go	Implements the new rename_column linter using TiDB AST specs.
pkg/lint/lint_rename_column_test.go	Adds test coverage for rename detection across ALTER variants.
pkg/lint/violation.go	Centralizes violation sorting/printing helpers used by CLI output.
pkg/lint/cmd_common.go	Removed after moving shared helper functions into violation.go.
.gitignore	Ignores bin/ output directory.

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[aparajon]

Should this be a higher severity?

[morgo]

For now most things are warnings. We will have to revisit all the severity levels though. I'd like to have a 1 pager which explains them and why.