merge: isolate agent cwd in .ideai/run/<id> (convention-file collision fix, §14.1)

crates/domain/src/profile.rs

@@ -96,7 +96,10 @@ pub struct AgentProfile {
     pub context_injection: ContextInjection,
     /// Optional detection command (e.g. `claude --version`).
     pub detect: Option<String>,
-    /// Working-directory template (e.g. `"{projectRoot}"`).
+    /// Working-directory template. Always `"{agentRunDir}"` (ARCHITECTURE §14.1):
+    /// an agent's PTY cwd is its isolated `.ideai/run/<agent-id>/` directory,
+    /// **never** the project root, so that N agents of the same profile never
+    /// collide on a single conventional file (`CLAUDE.md`, …) at the root.
     pub cwd_template: String,
 }