knowledge: reset local tree before pulling to avoid ff-only wedge

hive-c0re/src/workers/knowledge.rs

@@ -254,6 +254,21 @@ pub async fn pull(coord: &Coordinator) -> Result<()> {
         .args(["-C", LOCAL_DIR, "remote", "set-url", "origin", &plain])
         .output()
         .await;
+    // Discard any local modifications before pulling. Nothing in this
+    // codebase writes to `LOCAL_DIR` after the initial clone (`seed_readme`
+    // runs once, at creation, before any pull) — this working tree exists
+    // to mirror `origin/main`, not to be edited in place. A tracked file
+    // left dirty by any other means (a stray manual edit on the host, an
+    // interrupted prior operation) would otherwise abort the `--ff-only`
+    // merge below with "local changes would be overwritten", wedging
+    // every future pull the same way until someone notices and resets it
+    // by hand. Best-effort: a reset failure surfaces through the pull's
+    // own error below rather than needing its own branch here.
+    let _ = crate::lifecycle::git_command()
+        .args(["-C", LOCAL_DIR, "reset", "--hard", "HEAD"])
+        .output()
+        .await;
+
     let before = head_sha().await;
     // The repo is public (`ensure_knowledge_repo` makes it so), so an
     // unauthenticated pull is enough — but authenticate when a token is around,