feat: enforce output version v1 and add version subcommand

tests/cli_parse_tests.rs

@@ -26,3 +26,12 @@ fn parse_render_md_requires_input() {
         _ => panic!("expected render-md"),
     }
 }
+
+#[test]
+fn parse_version_subcommand() {
+    let cli = Cli::try_parse_from(["gitea-pr-review", "version"]).unwrap();
+    match cli.command {
+        Commands::Version => {}
+        _ => panic!("expected version"),
+    }
+}

tests/e2e_smoke_tests.rs

@@ -8,6 +8,7 @@ fn render_md_reads_json_and_outputs_markdown_to_stdout() {
     std::fs::write(
         input.path(),
         r#"{
+  "version": "v1",
   "meta": {
     "repo": "org/repo",
     "pr_index": 1,
@@ -52,6 +53,7 @@ fn render_md_writes_to_out_file_when_requested() {
     std::fs::write(
         input.path(),
         r#"{
+  "version": "v1",
   "meta": {
     "repo": "org/repo",
     "pr_index": 2,
@@ -291,6 +293,59 @@ fn fetch_writes_json_to_out_file_when_requested() {
     let written = std::fs::read_to_string(output.path()).unwrap();
     assert!(written.contains("\"repo\": \"org/repo\""));
     assert!(written.contains("\"pr_index\": 8"));
+    assert!(written.contains("\"version\": \"v1\""));
     assert!(written.contains("\"fetched_at\":"));
     assert!(written.contains("\"head_branch\": \"feature/y\""));
 }
+
+#[test]
+fn render_md_fails_when_version_mismatch() {
+    let input = NamedTempFile::new().unwrap();
+    std::fs::write(
+        input.path(),
+        r#"{
+  "version": "v2",
+  "meta": {
+    "repo": "org/repo",
+    "pr_index": 3,
+    "title": "t3",
+    "description": "PR body",
+    "fetched_at": "2026-04-08T12:34:56Z",
+    "state": "open",
+    "author": "a",
+    "base_branch": "main",
+    "head_branch": "f",
+    "created_at": "2026-04-08T10:00:00Z",
+    "updated_at": "2026-04-08T11:00:00Z",
+    "merged_at": null
+  },
+  "commits": [],
+  "diff_stat": {
+    "files_changed": 0,
+    "additions": 0,
+    "deletions": 0,
+    "files": []
+  },
+  "reviews": [],
+  "threads": []
+}"#,
+    )
+    .unwrap();
+
+    Command::cargo_bin("gitea-pr-review")
+        .unwrap()
+        .args(["render-md", "--in", input.path().to_str().unwrap()])
+        .assert()
+        .failure();
+}
+
+#[test]
+fn version_subcommand_prints_current_version() {
+    let assert = Command::cargo_bin("gitea-pr-review")
+        .unwrap()
+        .arg("version")
+        .assert()
+        .success();
+    let stdout = String::from_utf8(assert.get_output().stdout.clone()).unwrap();
+    assert_eq!(stdout.trim(), "v1");
+}

tests/normalize_tests.rs

@@ -145,7 +145,7 @@ fn normalize_groups_replies_and_sorts_threads_by_time() {
 
     assert_eq!(doc.meta.repo, "org/repo");
     assert_eq!(doc.meta.pr_index, 42);
-    assert_eq!(doc.meta.fetched_at.as_deref(), Some("2026-04-08T12:34:56Z"));
+    assert_eq!(doc.meta.fetched_at, "2026-04-08T12:34:56Z");
     assert_eq!(doc.meta.base_branch, "main");
     assert_eq!(doc.meta.head_branch, "feature/x");
 

tests/render_json_tests.rs

@@ -5,12 +5,13 @@ use gitea_pr_review::model::{
 #[test]
 fn model_json_roundtrip() {
     let doc = PrReviewDocument {
+        version: "v1".into(),
         meta: PrMeta {
             repo: "org/repo".into(),
             pr_index: 9,
             title: "feat: x".into(),
             description: Some("desc".into()),
-            fetched_at: Some("2026-04-08T12:34:56Z".into()),
+            fetched_at: "2026-04-08T12:34:56Z".into(),
             state: "open".into(),
             author: "alice".into(),
             base_branch: "main".into(),
@@ -50,7 +51,8 @@ fn model_json_roundtrip() {
 
     let encoded = serde_json::to_string(&doc).unwrap();
     let decoded: PrReviewDocument = serde_json::from_str(&encoded).unwrap();
+    assert_eq!(decoded.version, "v1");
     assert_eq!(decoded.meta.repo, "org/repo");
-    assert_eq!(decoded.meta.fetched_at.as_deref(), Some("2026-04-08T12:34:56Z"));
+    assert_eq!(decoded.meta.fetched_at, "2026-04-08T12:34:56Z");
     assert_eq!(decoded.threads[0].root_comment.body, "hello");
 }

tests/render_markdown_tests.rs

@@ -7,12 +7,13 @@ use gitea_pr_review::render::markdown::render_markdown;
 #[test]
 fn render_markdown_includes_expected_sections_and_preserves_comment_markdown() {
     let doc = PrReviewDocument {
+        version: "v1".into(),
         meta: PrMeta {
             repo: "org/repo".into(),
             pr_index: 7,
             title: "Fix parser".into(),
             description: Some("PR body".into()),
-            fetched_at: Some("2026-04-08T12:34:56Z".into()),
+            fetched_at: "2026-04-08T12:34:56Z".into(),
             state: "open".into(),
             author: "alice".into(),
             base_branch: "main".into(),
@@ -73,6 +74,7 @@ fn render_markdown_includes_expected_sections_and_preserves_comment_markdown() {
 
     assert!(md.contains("# org/repo `#7` Fix parser"));
     assert!(md.contains("## Metadata"));
+    assert!(md.contains("> version: v1"));
     assert!(md.contains("> fetched at: 2026-04-08T12:34:56Z"));
     assert!(md.contains("## Commits"));
     assert!(md.contains("## Diff Stat"));
@@ -96,12 +98,13 @@ fn render_markdown_includes_expected_sections_and_preserves_comment_markdown() {
 fn render_markdown_uses_minimal_fence_for_plain_text() {
     let body = "plain text";
     let doc = PrReviewDocument {
+        version: "v1".into(),
         meta: PrMeta {
             repo: "org/repo".into(),
             pr_index: 1,
             title: "T".into(),
             description: None,
-            fetched_at: None,
+            fetched_at: "2026-04-08T12:34:56Z".into(),
             state: "open".into(),
             author: "alice".into(),
             base_branch: "main".into(),