timeline

Respond in the user's preferred language (detect from their recent messages, or fall back to the language setting in CLAUDE.md).

Group the current branch's commit history into semantic phases along a timeline, and generate two review documents: architecture evolution + code review.

Arguments: $ARGUMENTS

• No arguments: diff against main...HEAD
• --base <branch>: specify a custom base branch for comparison

Core Concept

Unlike /qq:brief (produces architecture diff + PR checklist), this command groups commits by timeline phases, helping reviewers build a mental model in development order while preserving priority annotations.

Execution Steps

1. Collect Commit History

git log <base>..HEAD --oneline --reverse --format="%h %ai %s"

2. Group Commits into Semantic Phases

Grouping criteria (in order of priority):

1. Semantic affinity: consecutive commits on the same feature/subsystem go in the same group
2. Natural breakpoints: merge commits, date gaps > 1 day, module switches
3. Phase markers in commit messages: if a commit self-annotates with a Phase, respect that first

Each Phase requires:

• A semantic name (e.g. "Player Health System", not "Phase 1")
• Date range
• List of commits (hash + one-line description)
• One-sentence summary

Target: 5–10 Phases (too few loses timeline value; too many becomes per-commit annotation)

3. Analyze Changes per Phase

For each Phase:

git diff <phase_first_commit>~1..<phase_last_commit> --stat
git diff <phase_first_commit>~1..<phase_last_commit> -- '*.cs'

Read the full content of key changed files to understand context — not just diff fragments.

4. Generate Document A: Architecture Evolution Timeline

Format:

# Architecture Evolution Timeline

> X phases, Y commits, Z-day development span
> Branch: `<branch>`, base: `<base>`

---

## Phase 1: <Semantic Name> (<date range>, N commits)

> One-sentence summary

<details>
<summary>Commits</summary>

- `hash1` message1
- `hash2` message2
</details>

### Architecture Changes

#### [Tier 1] Change Title (if any)
**Scope**: ...
**Nature of change**: ...

\```mermaid
<diagram: show the architectural changes introduced in this phase, not the accumulated final state>
\```

#### [Tier 2] Change Title (if any)
...

### Dependencies Introduced This Phase
- `ModuleA` → `ModuleB` (new reference)

### Cumulative State
> Overall progress to this point: X completed, next phase will Y

---

## Phase 2: <Semantic Name> ...