cli: extract journal and misc commands, complete split

Move remaining extractable handlers into cli/journal.rs and cli/misc.rs.
Functions depending on main.rs helpers (cmd_journal_tail, cmd_journal_write,
cmd_load_context, cmd_cursor, cmd_daemon, cmd_digest, cmd_experience_mine,
cmd_apply_agent) remain in main.rs — next step is moving those helpers
to library code.

main.rs: 3130 → 1331 lines (57% reduction).
cli/ total: 1860 lines across 6 focused files.

Co-Authored-By: Kent Overstreet <kent.overstreet@linux.dev>

poc-memory/src/cli/journal.rs

@@ -0,0 +1,55 @@
+// cli/journal.rs — journal subcommand handlers
+
+use crate::store;
+use crate::store::StoreView;
+
+pub fn cmd_tail(n: usize, full: bool) -> Result<(), String> {
+    let path = crate::store::nodes_path();
+    if !path.exists() {
+        return Err("No node log found".into());
+    }
+
+    use std::io::BufReader;
+    let file = std::fs::File::open(&path)
+        .map_err(|e| format!("open {}: {}", path.display(), e))?;
+    let mut reader = BufReader::new(file);
+
+    // Read all entries, keep last N
+    let mut entries: Vec<crate::store::Node> = Vec::new();
+    while let Ok(msg) = capnp::serialize::read_message(&mut reader, capnp::message::ReaderOptions::new()) {
+        let log = msg.get_root::<crate::memory_capnp::node_log::Reader>()
+            .map_err(|e| format!("read log: {}", e))?;
+        for node_reader in log.get_nodes()
+            .map_err(|e| format!("get nodes: {}", e))? {
+            let node = crate::store::Node::from_capnp_migrate(node_reader)?;
+            entries.push(node);
+        }
+    }
+
+    let start = entries.len().saturating_sub(n);
+    for node in &entries[start..] {
+        let ts = if node.timestamp > 0 && node.timestamp < 4_000_000_000 {
+            crate::store::format_datetime(node.timestamp)
+        } else {
+            format!("(raw:{})", node.timestamp)
+        };
+        let del = if node.deleted { " [DELETED]" } else { "" };
+        if full {
+            eprintln!("--- {} (v{}) {} via {} w={:.3}{} ---",
+                node.key, node.version, ts, node.provenance, node.weight, del);
+            eprintln!("{}\n", node.content);
+        } else {
+            let preview = crate::util::first_n_chars(&node.content, 100).replace('\n', "\\n");
+            eprintln!("  {}  v{}  w={:.2}{}",
+                ts, node.version, node.weight, del);
+            eprintln!("  {}  via {}", node.key, node.provenance);
+            if !preview.is_empty() {
+                eprintln!("  {}", preview);
+            }
+            eprintln!();
+        }
+    }
+
+    Ok(())
+}
+