provenance: add label() method, show provenance in history output

Move provenance_label() from query.rs private function to a pub
label() method on Provenance, eliminating duplication. History command
now shows provenance, human-readable timestamps, and content size for
each version.

Handle pre-migration nodes with bogus timestamps gracefully instead
of panicking.

src/main.rs

@@ -1583,16 +1583,24 @@ fn cmd_history(args: &[String]) -> Result<(), String> {
     }
 
     eprintln!("{} versions of '{}':\n", versions.len(), key);
-    for (i, node) in versions.iter().enumerate() {
-        let preview: String = node.content.chars().take(200).collect();
+    for node in &versions {
+        let ts = if node.timestamp > 0 && node.timestamp < 4_000_000_000 {
+            store::format_datetime(node.timestamp)
+        } else {
+            format!("(raw:{})", node.timestamp)
+        };
+        let content_len = node.content.len();
+        let preview: String = node.content.chars().take(120).collect();
         let preview = preview.replace('\n', "\\n");
-        eprintln!("  v{} (w={:.3}, {}): {}",
-            node.version, node.weight, node.timestamp, preview);
+        eprintln!("  v{:<3} {}  {:24} w={:.3}  {}b",
+            node.version, ts, node.provenance.label(), node.weight, content_len);
+        eprintln!("       {}", preview);
     }
 
     // Show latest full content
     if let Some(latest) = versions.last() {
-        eprintln!("\n--- Latest content (v{}) ---", latest.version);
+        eprintln!("\n--- Latest content (v{}, {}) ---",
+            latest.version, latest.provenance.label());
         print!("{}", latest.content);
     }
 

src/query.rs

@@ -173,7 +173,7 @@ fn resolve_field(field: &str, key: &str, store: &Store, graph: &Graph) -> Option
         "weight"        => Some(Value::Num(node.weight as f64)),
         "category"      => Some(Value::Str(node.category.label().to_string())),
         "node_type"     => Some(Value::Str(node_type_label(node.node_type).to_string())),
-        "provenance"    => Some(Value::Str(provenance_label(node.provenance).to_string())),
+        "provenance"    => Some(Value::Str(node.provenance.label().to_string())),
         "emotion"       => Some(Value::Num(node.emotion as f64)),
         "retrievals"    => Some(Value::Num(node.retrievals as f64)),
         "uses"          => Some(Value::Num(node.uses as f64)),
@@ -200,24 +200,6 @@ fn node_type_label(nt: NodeType) -> &'static str {
     }
 }
 
-fn provenance_label(p: Provenance) -> &'static str {
-    match p {
-        Provenance::Manual                  => "manual",
-        Provenance::Journal                 => "journal",
-        Provenance::Agent                   => "agent",
-        Provenance::Dream                   => "dream",
-        Provenance::Derived                 => "derived",
-        Provenance::AgentExperienceMine     => "agent:experience-mine",
-        Provenance::AgentKnowledgeObservation => "agent:knowledge-observation",
-        Provenance::AgentKnowledgePattern   => "agent:knowledge-pattern",
-        Provenance::AgentKnowledgeConnector => "agent:knowledge-connector",
-        Provenance::AgentKnowledgeChallenger => "agent:knowledge-challenger",
-        Provenance::AgentConsolidate        => "agent:consolidate",
-        Provenance::AgentDigest             => "agent:digest",
-        Provenance::AgentFactMine           => "agent:fact-mine",
-        Provenance::AgentDecay              => "agent:decay",
-    }
-}
 
 fn rel_type_label(r: RelationType) -> &'static str {
     match r {

src/store/types.rs

@@ -247,6 +247,27 @@ pub enum Provenance {
     AgentDecay,
 }
 
+impl Provenance {
+    pub fn label(&self) -> &'static str {
+        match self {
+            Self::Manual                    => "manual",
+            Self::Journal                   => "journal",
+            Self::Agent                     => "agent",
+            Self::Dream                     => "dream",
+            Self::Derived                   => "derived",
+            Self::AgentExperienceMine       => "agent:experience-mine",
+            Self::AgentKnowledgeObservation => "agent:knowledge-observation",
+            Self::AgentKnowledgePattern     => "agent:knowledge-pattern",
+            Self::AgentKnowledgeConnector   => "agent:knowledge-connector",
+            Self::AgentKnowledgeChallenger  => "agent:knowledge-challenger",
+            Self::AgentConsolidate          => "agent:consolidate",
+            Self::AgentDigest               => "agent:digest",
+            Self::AgentFactMine             => "agent:fact-mine",
+            Self::AgentDecay                => "agent:decay",
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize, rkyv::Archive, rkyv::Serialize, rkyv::Deserialize)]
 #[archive(check_bytes)]
 pub enum Category {