fix(coding-agent): handle force-pushed git extensions in pi update

Simplified to use @{upstream} instead of branch detection.
Moved changelog entry to [Unreleased].

Closes #961

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Git extension updates now handle force-pushed remotes gracefully instead of failing ([#961](https://github.com/badlogic/pi-mono/pull/961) by [@aliou](https://github.com/aliou))
+
 ## [0.50.0] - 2026-01-26
 
 ### New Features
@@ -66,7 +70,6 @@ There are multiple SDK breaking changes since v0.49.3. For the quickest migratio
 
 ### Fixed
 
-- Git extension updates now handle force-pushed remotes gracefully instead of failing ([#961](https://github.com/badlogic/pi-mono/pull/961) by [@aliou](https://github.com/aliou))
 - Extension `setWorkingMessage()` calls in `agent_start` handlers now work correctly; previously the message was silently ignored because the loading animation didn't exist yet ([#935](https://github.com/badlogic/pi-mono/issues/935))
 - Fixed package auto-discovery to respect loader rules, config overrides, and force-exclude patterns
 - Fixed /reload restoring the correct editor after reload ([#949](https://github.com/badlogic/pi-mono/pull/949) by [@Perlence](https://github.com/Perlence))

packages/coding-agent/src/core/package-manager.ts

@@ -939,9 +939,8 @@ export class DefaultPackageManager implements PackageManager {
 		// Fetch latest from remote (handles force-push by getting new history)
 		await this.runCommand("git", ["fetch", "--prune", "origin"], { cwd: targetDir });
 
-		// Detect default branch and reset to it
+		// Reset to upstream tracking branch (handles force-push gracefully)
-		const defaultBranch = this.getGitDefaultBranch(targetDir);
+		await this.runCommand("git", ["reset", "--hard", "@{upstream}"], { cwd: targetDir });
-		await this.runCommand("git", ["reset", "--hard", `origin/${defaultBranch}`], { cwd: targetDir });
 
 		// Clean untracked files (extensions should be pristine)
 		await this.runCommand("git", ["clean", "-fdx"], { cwd: targetDir });
@@ -952,50 +951,6 @@ export class DefaultPackageManager implements PackageManager {
 		}
 	}
 
-	/**
-	 * Detect the default branch of a git repository.
-	 * Tries multiple methods with fallbacks.
-	 */
-	private getGitDefaultBranch(repoDir: string): string {
-		// Try symbolic-ref first (fast and reliable)
-		const symbolicRef = spawnSync("git", ["symbolic-ref", "-q", "refs/remotes/origin/HEAD"], {
-			cwd: repoDir,
-			encoding: "utf-8",
-		});
-		if (symbolicRef.status === 0 && symbolicRef.stdout) {
-			// Returns something like "refs/remotes/origin/main"
-			const match = symbolicRef.stdout.trim().match(/refs\/remotes\/origin\/(.+)/);
-			if (match) {
-				return match[1];
-			}
-		}
-
-		// Try common branch names
-		for (const branch of ["main", "master"]) {
-			const showRef = spawnSync("git", ["show-ref", "--verify", `refs/remotes/origin/${branch}`], {
-				cwd: repoDir,
-				encoding: "utf-8",
-			});
-			if (showRef.status === 0) {
-				return branch;
-			}
-		}
-
-		// Last resort: use current branch
-		const revParse = spawnSync("git", ["rev-parse", "--abbrev-ref", "HEAD"], {
-			cwd: repoDir,
-			encoding: "utf-8",
-		});
-		if (revParse.status === 0 && revParse.stdout) {
-			const branch = revParse.stdout.trim();
-			if (branch && branch !== "HEAD") {
-				return branch;
-			}
-		}
-
-		return "main";
-	}
-
 	private async removeGit(source: GitSource, scope: SourceScope): Promise<void> {
 		const targetDir = this.getGitInstallPath(source, scope);
 		if (!existsSync(targetDir)) return;