[Learning Capture] Implement command correction (learn correct subcommand)

[AlexMikhalev]

Description

The terraphim-agent learn correct subcommand is documented in the CLI but returns "(Not yet implemented)" when invoked.

Current Behavior

$ terraphim-agent learn correct <ID> --correction "Use 'echo test' instead"
Adding correction to learning <ID>: Use 'echo test' instead
(Not yet implemented)

Expected Behavior

The command should add a correction to an existing learning document, enabling:

1. Recording the correct command that should have been used
2. Querying learnings to show both the failed command and the correction
3. Future auto-suggestion of corrections when similar failed commands are detected

Use Case

When a user runs a command that fails and gets captured:

$ bad-cmd --test
bad-cmd: command not found

They can later add a correction:

$ terraphim-agent learn correct <learning-id> --correction "Use 'good-cmd --test' instead"

This enables the learning system to suggest corrections for similar failures.

Related

• Issue [Learning Capture] Step 3: Implement capture.rs #531: [Learning Capture] Step 3: Implement capture.rs (completed)
• Issue [Learning Capture] Step 4: Add CLI learn subcommand #532: [Learning Capture] Step 4: Add CLI learn subcommand (completed)
• Current implementation: terraphim_agent/src/learnings/correct.rs (stub)

Acceptance Criteria

• terraphim-agent learn correct <ID> --correction "..." adds correction to learning file
• terraphim-agent learn query displays corrections if present
• Correction is persisted in learning markdown frontmatter
• Works with both global and project-specific learnings

Co-Authored-By: Terraphim AI

[AlexMikhalev]

Implemented in commit efc13489 on branch feat/router-tracing

Changes

crates/terraphim_agent/src/learnings/capture.rs:

• Added LearningError::NotFound variant
• Added correct_learning(storage_dir, id, correction) -- finds learning by exact ID or prefix match, updates correction field, overwrites markdown file
• 3 new tests: test_correct_learning, test_correct_learning_not_found, test_correct_learning_prefix_match

crates/terraphim_agent/src/learnings/mod.rs:

• Exported correct_learning

crates/terraphim_agent/src/main.rs:

• Replaced both TODO stubs (CLI + REPL) with real correct_learning() call
• Added correction display to learn query output (matching existing learn list behavior)

All acceptance criteria met

• terraphim-agent learn correct <ID> --correction "..." adds correction to learning file
• terraphim-agent learn query displays corrections if present
• Correction persisted in learning markdown frontmatter
• Works with both project-specific and global learnings (uses config.storage_location())
• Prefix matching on IDs for convenience (UUIDs are long)

Tests

41 learnings tests passing (3 new), all pre-commit checks green.