sessions : registre des sessions + commande am sessions (issue #5) - lifecycle agent/repl, reconciliation des sessions interrompues, compteur sessions_count, filtres agent/projet/statut, show avec extrait de log

src/help.rs

@@ -177,6 +177,27 @@ pub static HELP_SPECS: &[HelpSpec] = &[
             HelpExample { desc: "Show one agent.", code: "status claude-code" },
         ],
     },
+    HelpSpec {
+        name: "sessions",
+        category: "Commands",
+        usage: "sessions {flags} [agent]",
+        about: "List the sessions of every agent and of the interactive shell.",
+        search_terms: &["session", "history", "log"],
+        flags: &[
+            HelpFlag { short: "", long: "--project", value: "PROJECT", desc: "Only sessions of this project" },
+            HelpFlag { short: "", long: "--status", value: "STATUS", desc: "Only sessions with this status (running, stopped, failed, interrupted)" },
+            HelpFlag { short: "", long: "--show", value: "ID", desc: "Show one session in detail (summary + log excerpt)" },
+        ],
+        subcommands: &[],
+        parameters: &[
+            HelpParam { name: "agent", typ: "string", desc: "Only sessions of this agent" },
+        ],
+        io: None,
+        examples: &[
+            HelpExample { desc: "List recent sessions.", code: "sessions" },
+            HelpExample { desc: "Show one session with its log excerpt.", code: "sessions --show 20260815_143926_a1b2c3" },
+        ],
+    },
     HelpSpec {
         name: "search",
         category: "Commands",