feat: add VCS workflows and cycle extension

skills/agent-workflow-host/SKILL.md

@@ -14,11 +14,12 @@ Support these explicit operations:
 ```text
 $agent-workflow-host 执行已确认计划
 $agent-workflow-host 使用 claude 执行已确认计划
+$agent-workflow-host 使用 svn 执行已确认计划
 $agent-workflow-host 继续 <run-id>
 $agent-workflow-host 查看 <run-id>
 $agent-workflow-host 清理后重试 <run-id>
 $agent-workflow-host 执行器重试 <run-id>
-$agent-workflow-host 执行器重试 <run-id>
+$agent-workflow-host 延长 <run-id> 添加 <n> 个周期
 $agent-workflow-host 中止 <run-id> 原因：需求变化
 $agent-workflow-host 日志 <run-id> [--follow]
 ```
@@ -34,15 +35,16 @@ $agent-workflow-host 日志 <run-id> [--follow]
 - Codex owns plan normalization, finding classification, verification, and acceptance.
 - The executor owns implementation, tests, and fixes. During an active workflow, Codex must not edit target repository files itself.
 - `agent-workflow review` only prepares evidence for Codex. Do not invoke another reviewer as an acceptance gate.
-- Never run or authorize `git commit`, `git push`, `git reset`, history rewriting, or branch deletion.
+- Never run or authorize `git commit`, `git push`, `git reset`, `svn commit`, `svn switch`, `svn update`, history rewriting, or branch deletion.
 - Never broaden the approved scope or silently change requirements after start. Abort and create a new plan when requirements materially change.
 
 ## Start A Confirmed Plan
 
-1. Resolve the target Git root and inspect the repository before execution.
+1. Resolve the target VCS root (Git or SVN) and inspect the repository before execution.
 2. Run these preflight checks:
    - `command -v agent-workflow`
-   - `git status --porcelain` must be empty.
+   - For Git: `git status --porcelain` must be empty.
+   - For SVN: `svn status` must show a clean working copy with no mixed revisions.
    - Probe the selected executor with `<executor> --version`.
    - Confirm no unresolved active workflow prevents a new run.
 3. Do not install tools, commit, or stash automatically. Report the exact missing prerequisite and stop.
@@ -64,7 +66,7 @@ $agent-workflow-host 日志 <run-id> [--follow]
 7. Start the run and record the emitted run ID, then immediately print a logs-follow command the user can run independently:
 
 ```bash
-agent-workflow start --plan <temp-plan.json> --executor <reasonix|claude|agy>
+agent-workflow start --plan <temp-plan.json> --executor <reasonix|claude|agy> [--vcs <git|svn>]
 ```
 
 After starting, announce:
@@ -72,7 +74,7 @@ After starting, announce:
 Run <run-id> started. Monitor live output: agent-workflow logs --run <run-id> --follow
 ```
 
-Honor an explicit `max-cycles` argument. Otherwise use project configuration and workflow defaults.
+Honor an explicit `max-cycles` argument or `--vcs` flag. Otherwise use project configuration and workflow defaults. VCS is auto-detected if not specified.
 
 ## Drive The State Machine
 
@@ -143,24 +145,42 @@ Create `HostDecisionV1` in the temporary directory:
 
 After `fix`, repeat review and decision for the new cycle. Respect the configured cycle budget and the engine's persistence/oscillation stop conditions.
 
-## Resume, Inspect, Or Abort
+## Resume, Inspect, Extend, Or Abort
 
 - For `查看 <run-id>`, run `agent-workflow status --run <run-id> --json`, summarize it, and do not advance the workflow.
 - For `继续 <run-id>`, read status first, then continue from `awaiting_review`, `awaiting_scope_resolution`, or `awaiting_host`. Read the persisted state and referenced cycle artifacts when earlier command output is no longer in context; do not reconstruct findings from memory.
-- For `清理后重试 <run-id>`, run `agent-workflow retry-review --run <run-id>` after the approved scope artifacts have been removed. It must refuse when HEAD drift or out-of-scope paths remain.
-- For `执行器重试 <run-id>`, run `agent-workflow retry-execute --run <run-id>` after the external cause of an executor failure is cleared (e.g., session conflict resolved, transient error gone). It preserves failed attempt logs and reuses the same session handle. Initial-cycle retries continue from the original plan; later-cycle retries resume from the preceding decision. Refuses when HEAD has drifted, scope violations exist, or the cycle already produced review artifacts.
-- Treat `completed`, `needs_human`, `blocked`, `budget_exhausted`, and `aborted` as terminal. Report them instead of attempting another cycle.
+- For `清理后重试 <run-id>`, run `agent-workflow retry-review --run <run-id>` after the approved scope artifacts have been removed. It must refuse when baseline drift or out-of-scope paths remain.
+- For `执行器重试 <run-id>`, run `agent-workflow retry-execute --run <run-id>` after the external cause of an executor failure is cleared (e.g., session conflict resolved, transient error gone). It preserves failed attempt logs and reuses the same session handle. Initial-cycle retries continue from the original plan; later-cycle retries resume from the preceding decision. Refuses when baseline has drifted, scope violations exist, or the cycle already produced review artifacts.
+- For `延长 <run-id> 添加 <n> 个周期`, run `agent-workflow extend --run <run-id> --additional-cycles <n>` to extend a `budget_exhausted` run. This requires: the run ended at `budget_exhausted`, has a valid session handle, the last decision was `fix`, baseline hasn't drifted, and scope is clean. Returns to `awaiting_host` state to continue the same executor session.
+- Treat `completed`, `needs_human`, `blocked`, and `aborted` as terminal. Report them instead of attempting another cycle.
+- `budget_exhausted` is terminal but can be extended with the extend command if all conditions are met.
 - For an explicit abort, run `agent-workflow abort --run <run-id> --reason <text>` and report the resulting status.
 
 ## Failure Handling
 
-- Missing session handle, executor failure, or HEAD drift must stop as `blocked`; do not work around the gate.
+- Missing session handle, executor failure, or baseline drift (Git HEAD change, SVN revision change) must stop as `blocked`; do not work around the gate.
 - When a resume failed before producing cycle artifacts because the same session was busy, ask the user to close the owning executor process, then use `retry-execute`; never kill an unrelated process automatically.
 - Out-of-scope edits must enter `awaiting_scope_resolution`; inspect and remediate them through the same executor session. Repeated identical violations must stop as `needs_human`.
 - Same finding in consecutive reviews or disappear/reappear oscillation must stop as `needs_human` when the engine reports non-convergence.
+- If the cycle budget is exhausted and more work remains, explain the `extend` command option to the user.
 - If interrupted, preserve the run ID. A later explicit `继续 <run-id>` invocation resumes from durable state.
 - If the user changes requirements, abort the active run and return to plan discussion. Do not mutate the frozen plan in place.
 
+## VCS-Specific Guidance
+
+### Git Workflows
+- Standard baseline tracking with HEAD SHA
+- Diff includes tracked changes and unversioned additions
+- Scope checking via `git diff --name-only` and `git ls-files`
+
+### SVN Workflows (Strict Mode)
+- Baseline includes repository URL, UUID, and single working revision
+- Before starting: verify `svn info` shows consistent state, no mixed revisions
+- Diff includes tracked modifications, unversioned additions, deletions, and property changes
+- The executor never runs `svn commit`, `svn switch`, or `svn update`
+- Reject runs with switched paths, externals, conflicts, or incomplete states
+- If mixed revisions detected: stop and instruct user to run `svn update`
+
 ## Final Report
 
 Report: