migrate agent output to capnp store, add provenance tracking

All agent output now goes to the store as nodes instead of
markdown/JSON files. Each node carries a Provenance enum identifying
which agent created it (AgentDigest, AgentConsolidate, AgentFactMine,
AgentKnowledgeObservation, etc — 14 variants total).

Store changes:
- upsert_provenance() method for agent-created nodes
- Provenance enum expanded from 5 to 14 variants

Agent changes:
- digest: writes to store nodes (daily-YYYY-MM-DD.md etc)
- consolidate: reports/actions/logs stored as _consolidation-* nodes
- knowledge: depth DB and agent output stored as _knowledge-* nodes
- enrich: experience-mine results go directly to store
- llm: --no-session-persistence prevents transcript accumulation

Deleted: 14 Python/shell scripts replaced by Rust implementations.

src/query.rs

@@ -202,11 +202,20 @@ 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::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",
     }
 }