feat(p10-1a-1): add Metadata.repo / git_branch / git_commit / code_lang

Four optional, serde-skipped-when-None fields added to `Metadata` for
code ingest context. All 11 downstream construction sites patched with
`repo: None, git_branch: None, git_commit: None, code_lang: None`.
Full workspace check (`--tests`) and per-crate test suite pass clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/kebab-chunk/src/md_heading_v1.rs

@@ -472,6 +472,10 @@ mod tests {
                 trust_level: TrustLevel::Primary,
                 user_id_alias: None,
                 user: Default::default(),
+                repo: None,
+                git_branch: None,
+                git_commit: None,
+                code_lang: None,
             },
             provenance: Provenance { events: vec![] },
             parser_version: kebab_core::ParserVersion("test-parser-0".into()),

crates/kebab-chunk/src/pdf_page_v1.rs

@@ -347,6 +347,10 @@ mod tests {
                 trust_level: TrustLevel::Primary,
                 user_id_alias: None,
                 user: Default::default(),
+                repo: None,
+                git_branch: None,
+                git_commit: None,
+                code_lang: None,
             },
             provenance: Provenance { events: vec![] },
             parser_version,
@@ -512,6 +516,10 @@ mod tests {
                 trust_level: TrustLevel::Primary,
                 user_id_alias: None,
                 user: Default::default(),
+                repo: None,
+                git_branch: None,
+                git_commit: None,
+                code_lang: None,
             },
             provenance: Provenance { events: vec![] },
             parser_version,

crates/kebab-core/src/metadata.rs

@@ -17,6 +17,25 @@ pub struct Metadata {
     pub user_id_alias: Option<String>,
     /// Frontmatter keys we don't recognise are preserved here per §0 Q9.
     pub user: Map<String, Value>,
+
+    /// p10-1A-1: name of the source repo if the file lives inside a git
+    /// working tree (`.git/` walk-up). null otherwise.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub repo: Option<String>,
+
+    /// p10-1A-1: HEAD branch at ingest time. null when no repo or detached HEAD.
+    /// Informational only — current-state observability, not a partition key.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub git_branch: Option<String>,
+
+    /// p10-1A-1: HEAD commit (40-hex) at ingest time. null when no repo.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub git_commit: Option<String>,
+
+    /// p10-1A-1: programming language identifier (lowercase canonical). null
+    /// for markdown / pdf / image. Set by `kebab_parse_code::lang::code_lang_for_path`.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub code_lang: Option<String>,
 }
 
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, Serialize, Deserialize)]
@@ -66,3 +85,54 @@ pub enum ProvenanceKind {
     Warning,
     Error,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn metadata_repo_fields_default_to_none_and_omit_when_serialized() {
+        let m = Metadata {
+            aliases: vec![],
+            tags: vec![],
+            created_at: time::OffsetDateTime::UNIX_EPOCH,
+            updated_at: time::OffsetDateTime::UNIX_EPOCH,
+            source_type: SourceType::Markdown,
+            trust_level: TrustLevel::Primary,
+            user_id_alias: None,
+            user: Default::default(),
+            repo: None,
+            git_branch: None,
+            git_commit: None,
+            code_lang: None,
+        };
+        let v = serde_json::to_value(&m).unwrap();
+        assert!(v.get("repo").is_none());
+        assert!(v.get("git_branch").is_none());
+        assert!(v.get("git_commit").is_none());
+        assert!(v.get("code_lang").is_none());
+    }
+
+    #[test]
+    fn metadata_repo_fields_present_when_some() {
+        let m = Metadata {
+            aliases: vec![],
+            tags: vec![],
+            created_at: time::OffsetDateTime::UNIX_EPOCH,
+            updated_at: time::OffsetDateTime::UNIX_EPOCH,
+            source_type: SourceType::Markdown,
+            trust_level: TrustLevel::Primary,
+            user_id_alias: None,
+            user: Default::default(),
+            repo: Some("kebab".into()),
+            git_branch: Some("main".into()),
+            git_commit: Some("a".repeat(40)),
+            code_lang: Some("rust".into()),
+        };
+        let v = serde_json::to_value(&m).unwrap();
+        assert_eq!(v["repo"], "kebab");
+        assert_eq!(v["git_branch"], "main");
+        assert_eq!(v["git_commit"].as_str().unwrap().len(), 40);
+        assert_eq!(v["code_lang"], "rust");
+    }
+}

crates/kebab-normalize/src/lib.rs

@@ -467,6 +467,10 @@ mod tests {
             trust_level: TrustLevel::Primary,
             user_id_alias: None,
             user,
+            repo: None,
+            git_branch: None,
+            git_commit: None,
+            code_lang: None,
         }
     }
 

crates/kebab-parse-image/src/lib.rs

@@ -190,6 +190,10 @@ impl Extractor for ImageExtractor {
             trust_level: TrustLevel::Primary,
             user_id_alias: None,
             user,
+            repo: None,
+            git_branch: None,
+            git_commit: None,
+            code_lang: None,
         };
 
         tracing::debug!(

crates/kebab-parse-md/src/frontmatter.rs

@@ -471,6 +471,10 @@ fn derive_metadata(
         trust_level,
         user_id_alias,
         user,
+        repo: None,
+        git_branch: None,
+        git_commit: None,
+        code_lang: None,
     }
 }
 

crates/kebab-parse-pdf/src/lib.rs

@@ -194,6 +194,10 @@ impl Extractor for PdfTextExtractor {
             trust_level: TrustLevel::Primary,
             user_id_alias: None,
             user,
+            repo: None,
+            git_branch: None,
+            git_commit: None,
+            code_lang: None,
         };
 
         tracing::debug!(

crates/kebab-store-sqlite/tests/idempotency.rs

@@ -42,6 +42,10 @@ fn make_metadata() -> Metadata {
         trust_level: TrustLevel::Primary,
         user_id_alias: None,
         user: Default::default(),
+        repo: None,
+        git_branch: None,
+        git_commit: None,
+        code_lang: None,
     }
 }
 

crates/kebab-store-sqlite/tests/incremental_ingest.rs

@@ -51,6 +51,10 @@ fn make_doc() -> CanonicalDocument {
         trust_level: TrustLevel::Primary,
         user_id_alias: None,
         user: Default::default(),
+        repo: None,
+        git_branch: None,
+        git_commit: None,
+        code_lang: None,
     };
     CanonicalDocument {
         doc_id,

crates/kebab-store-sqlite/tests/list_docs.rs

@@ -54,6 +54,10 @@ fn make_doc(
         trust_level: trust,
         user_id_alias: None,
         user: Default::default(),
+        repo: None,
+        git_branch: None,
+        git_commit: None,
+        code_lang: None,
     };
     let doc = CanonicalDocument {
         doc_id,

crates/kebab-tui/tests/inspect.rs

@@ -79,6 +79,10 @@ fn make_doc() -> CanonicalDocument {
             trust_level: TrustLevel::Primary,
             user_id_alias: None,
             user,
+            repo: None,
+            git_branch: None,
+            git_commit: None,
+            code_lang: None,
         },
         provenance: Provenance {
             events: vec![ProvenanceEvent {