- Generate base command using cobra-cli
- Register as subcommand of patch
- Add patch-id argument placeholder
- Verify basic command execution

Related Issue: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

Add methods to find patch application commits and extract old values:
- tissue.Client.FindPatchApplicationCommit: searches commit history with pagination
- tissue.Client.GetCommitDiff: retrieves commit diffs
- patch.ExtractOldValues: parses diffs to extract previous attribute values

The revert command now successfully:
- Retrieves patch metadata
- Finds the commit that applied the patch
- Extracts old attribute values from git diff
- Logs all extracted data for verification

Next: Create revert patch operations and execute deletion/creation

Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

Enhance patch MR template to distinguish revert operations:
- Add conditional logic to show revert context in MR description
- Parse original patch ID from RelatedTo field
- Use Origin field to detect revert patches
- No signature changes to createPatchMergeRequest

MR descriptions now show:
- Standard patches: 'adds the patch ID...'
- Revert patches: 'reverts patch X by deleting it and creating...'

Verified: MR
https://ops.gitlab.net/gitlab-com/gl-infra/cells/tissue/-/merge_requests/1142
shows correct revert description

Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

   - Extract extractValuesFromCellFile helper to reduce nesting
   - Use JSON parsing instead of regex for old value extraction
   - Use SearchCommits API instead of pagination
   - Add proper error handling for all operations

   Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

   Add table-driven tests covering:
   - CreateRevertOperations: operation creation logic
   - extractValuesFromCellFile: JSON parsing and extraction
   - ExtractOldValues: complete value extraction flow
   - FindPatchApplicationCommit: commit search logic

   All tests use mocked GitLab API responses following
   existing ringctl testing patterns.

   Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

Add `ringctl patch invert` to automate patch inversion during incident
response. Extracts old values from git history, creates invert patch
with commit references, and deletes failed patch in single MR.

Key changes:
- Add InvertInfo struct (patch ID, applied SHA, parent SHA)
- Implement ExtractOldValues using Compare API and JSON parsing
- Add FindPatchApplicationCommit using Search API
- Enhance MR template with clickable commit links
- Add 9 comprehensive unit tests
- Validate only 'replace' operations (fail fast on others)

Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

Add `ringctl patch invert` to automate patch inversion during incident
response. Extracts old values from git history, creates invert patch
with commit references, and deletes failed patch in single MR.

Key changes:
- Add InvertInfo struct (patch ID, applied SHA, parent SHA)
- Implement ExtractOldValues using Compare API and JSON parsing
- Add FindPatchApplicationCommit using Search API
- Enhance MR template with clickable commit links
- Add 9 comprehensive unit tests
- Validate only 'replace' operations (fail fast on others)

Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

Add `ringctl patch invert` to automate patch inversion during incident
response. Extracts old values from git history, creates invert patch
with commit references, and deletes failed patch in single MR.

Key changes:
- Add InvertInfo struct (patch ID, applied SHA, parent SHA)
- Implement ExtractOldValues using Compare API and JSON parsing
- Add FindPatchApplicationCommit using Search API
- Enhance MR template with clickable commit links
- Add 9 comprehensive unit tests
- Validate only 'replace' operations (fail fast on others)

Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

Add `ringctl patch invert` to automate patch inversion during incident
response. Extracts old values from git history, creates invert patch
with commit references, and deletes failed patch in single MR.

Key changes:
- Add InvertInfo struct (patch ID, applied SHA, parent SHA)
- Implement ExtractOldValues using Compare API and JSON parsing
- Add FindPatchApplicationCommit using Search API
- Enhance MR template with clickable commit links
- Add 9 comprehensive unit tests
- Validate only 'replace' operations (fail fast on others)

Related: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/21502

feat: add `ringctl patch invert` command, supporting inversion of the `replace` operation

See merge request !361