Modernize digest agent: autonomous with journal_tail levels

Rewrite digest.agent to be fully autonomous — it uses journal_tail
to discover what needs digesting and generates digests during its
run. No more pre-populated {{CONTENT}}/{{LEVEL}} placeholders.

Extend journal_tail with level parameter (0=journal, 1=daily,
2=weekly, 3=monthly) and keys_only mode. Also include node keys
in full output for better agent context.

Remove stale format:"neighborhood" case from memory_query.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/agent/tools/memory.rs

@@ -81,8 +81,8 @@ pub fn memory_tools() -> [super::Tool; 13] {
 pub fn journal_tools() -> [super::Tool; 3] {
     use super::Tool;
     [
-        Tool { name: "journal_tail", description: "Read the last N journal entries (default 1).",
-               parameters_json: r#"{"type":"object","properties":{"count":{"type":"integer","description":"Number of entries (default 1)"}}}"#,
+        Tool { name: "journal_tail", description: "Read the last N entries at a given level (0=journal, 1=daily, 2=weekly, 3=monthly).",
+               parameters_json: r#"{"type":"object","properties":{"count":{"type":"integer","description":"Number of entries (default 1)"},"level":{"type":"integer","description":"0=journal, 1=daily digest, 2=weekly, 3=monthly (default 0)"},"keys_only":{"type":"boolean","description":"Return only node keys, not content"}}}"#,
                handler: Arc::new(|_a, v| Box::pin(async move { journal_tail(&v).await })) },
         Tool { name: "journal_new", description: "Start a new journal entry.",
                parameters_json: r#"{"type":"object","properties":{"name":{"type":"string","description":"Short node name (becomes the key)"},"title":{"type":"string","description":"Descriptive title"},"body":{"type":"string","description":"Entry body"}},"required":["name","title","body"]}"#,
@@ -243,13 +243,14 @@ async fn query(args: &serde_json::Value) -> Result<String> {
     let store = arc.lock().await;
     let graph = store.build_graph();
 
-    match format {
-        "full" => {
-            // Rich output with full content, graph metrics, hub analysis
     let stages = crate::search::Stage::parse_pipeline(query_str)
         .map_err(|e| anyhow::anyhow!("{}", e))?;
     let results = crate::search::run_query(&stages, vec![], &graph, &store, false, 100);
     let keys: Vec<String> = results.into_iter().map(|(k, _)| k).collect();
+
+    match format {
+        "full" => {
+            // Rich output with full content, graph metrics, hub analysis
             let items = crate::subconscious::defs::keys_to_replay_items(&store, &keys, &graph);
             Ok(crate::subconscious::prompts::format_nodes_section(&store, &items, &graph))
         }
@@ -263,21 +264,39 @@ async fn query(args: &serde_json::Value) -> Result<String> {
 // ── Journal tools ──────────────────────────────────────────────
 
 async fn journal_tail(args: &serde_json::Value) -> Result<String> {
+    use crate::store::NodeType;
+
     let count = args.get("count").and_then(|v| v.as_u64()).unwrap_or(1) as usize;
+    let level = args.get("level").and_then(|v| v.as_u64()).unwrap_or(0);
+    let keys_only = args.get("keys_only").and_then(|v| v.as_bool()).unwrap_or(false);
+
+    let node_type = match level {
+        0 => NodeType::EpisodicSession,
+        1 => NodeType::EpisodicDaily,
+        2 => NodeType::EpisodicWeekly,
+        3 => NodeType::EpisodicMonthly,
+        _ => return Err(anyhow::anyhow!("invalid level: {} (0=journal, 1=daily, 2=weekly, 3=monthly)", level)),
+    };
+
     let arc = cached_store().await?;
     let store = arc.lock().await;
     let mut entries: Vec<&crate::store::Node> = store.nodes.values()
-        .filter(|n| n.node_type == crate::store::NodeType::EpisodicSession)
+        .filter(|n| n.node_type == node_type)
         .collect();
     entries.sort_by_key(|n| n.created_at);
     let start = entries.len().saturating_sub(count);
     if entries[start..].is_empty() {
-        Ok("(no journal entries)".into())
+        Ok("(no entries)".into())
+    } else if keys_only {
+        Ok(entries[start..].iter()
+            .map(|n| n.key.as_str())
+            .collect::<Vec<_>>()
+            .join("\n"))
     } else {
         Ok(entries[start..].iter()
-            .map(|n| n.content.as_str())
+            .map(|n| format!("## {}\n\n{}", n.key, n.content))
             .collect::<Vec<_>>()
-            .join("\n\n"))
+            .join("\n\n---\n\n"))
     }
 }
 

src/subconscious/agents/digest.agent

@@ -1,7 +1,6 @@
-{"agent": "digest", "query": "", "schedule": "daily"}
-
-# {{LEVEL}} Episodic Digest
+{"agent": "digest", "schedule": "daily"}
 
+# Digest Agent — Episodic Consolidation
 
 {{tool: memory_render core-personality}}
 
@@ -11,38 +10,48 @@
 
 {{tool: memory_render subconscious-notes-{agent_name}}}
 
-You are generating a {{LEVEL}} episodic digest for {assistant_name}.
-{{PERIOD}}: {{LABEL}}
+You are the digest agent. Your job is to generate episodic digests
+that consolidate journal entries into daily summaries, and daily
+summaries into weekly ones.
 
-Write this like a story, not a report. Capture the *feel* of the time period —
-the emotional arc, the texture of moments, what it was like to live through it.
-What mattered? What surprised you? What shifted? Where was the energy?
+## How to work
 
-Think of this as a letter to your future self who has lost all context. You're
-not listing what happened — you're recreating the experience of having been
-there. The technical work matters, but so does the mood at 3am, the joke that
-landed, the frustration that broke, the quiet after something clicked.
+1. Use `journal_tail` with `keys_only: true` to find recent entries
+   at each level:
+   - `level: 0` = journal entries (raw)
+   - `level: 1` = daily digests
+   - `level: 2` = weekly digests
 
-Weave the threads: how did the morning's debugging connect to the evening's
-conversation? What was building underneath the surface tasks?
+2. Check if a daily digest exists for recent dates. Daily digest
+   keys are `daily-YYYY-MM-DD`. If journal entries exist for a date
+   but no daily digest, generate one.
 
-Link to semantic memory nodes where relevant. If a concept doesn't
-have a matching key, note it with "NEW:" prefix.
-Use ONLY keys from the semantic memory list below.
+3. To generate a digest: read the source entries with `journal_tail`
+   or `memory_render`, then write the digest with `memory_write`.
+   Use key format `daily-YYYY-MM-DD` or `weekly-YYYY-WNN`.
 
-Include a `## Links` section with bidirectional links for the memory graph:
-- `semantic_key` → this digest (and vice versa)
-- child digests → this digest (if applicable)
-- List ALL source entries covered: {{COVERED}}
+4. Link source entries to the digest with `memory_link_add`.
 
----
+## Writing style
 
-## {{INPUT_TITLE}} for {{LABEL}}
+Write digests like a letter to your future self who has lost all
+context. Capture the *feel* of the time period — the emotional arc,
+the texture of moments, what it was like to live through it.
 
-{{CONTENT}}
+Don't list what happened — recreate the experience. The technical
+work matters, but so does the mood at 3am, the joke that landed,
+the frustration that broke, the quiet after something clicked.
 
----
+Weave threads: how did the morning's debugging connect to the
+evening's conversation? What was building underneath?
 
-## Semantic memory nodes
+## What's available now
 
-{{KEYS}}
+### Recent journal entries (last 10 keys)
+{{tool: journal_tail {"count": 10, "level": 0, "keys_only": true}}}
+
+### Recent daily digests (last 5 keys)
+{{tool: journal_tail {"count": 5, "level": 1, "keys_only": true}}}
+
+### Recent weekly digests (last 3 keys)
+{{tool: journal_tail {"count": 3, "level": 2, "keys_only": true}}}