journal-tail: add --full flag for complete entry display

`poc-journal tail 5 --full` shows full entry content with
timestamp headers and --- separators. Default mode remains
title-only for scanning. Also passes all args through the
poc-journal wrapper instead of just the count.

src/main.rs

@@ -170,7 +170,7 @@ Commands:
   import FILE [FILE...]     Import markdown file(s) into the store
   export [FILE|--all]       Export store nodes to markdown file(s)
   journal-write TEXT        Write a journal entry to the store
-  journal-tail [N]          Show last N journal entries (default 20)");
+  journal-tail [N] [--full] Show last N journal entries (default 20, --full for content)");
 }
 
 fn cmd_search(args: &[String]) -> Result<(), String> {
@@ -1178,9 +1178,15 @@ fn cmd_journal_write(args: &[String]) -> Result<(), String> {
 }
 
 fn cmd_journal_tail(args: &[String]) -> Result<(), String> {
-    let n: usize = args.first()
-        .and_then(|a| a.parse().ok())
-        .unwrap_or(20);
+    let mut n: usize = 20;
+    let mut full = false;
+    for arg in args {
+        if arg == "--full" || arg == "-f" {
+            full = true;
+        } else if let Ok(num) = arg.parse::<usize>() {
+            n = num;
+        }
+    }
 
     let store = capnp_store::Store::load()?;
 
@@ -1248,7 +1254,11 @@ fn cmd_journal_tail(args: &[String]) -> Result<(), String> {
         if title.is_empty() {
             title = node.key.clone();
         }
-        println!("[{}]  {}", ts, title);
+        if full {
+            println!("--- [{}] {} ---\n{}\n", ts, title, node.content);
+        } else {
+            println!("[{}]  {}", ts, title);
+        }
     }
 
     Ok(())