fix(opencode): use commands/ directory (plural) to match OpenCode docs (#2453)

* fix(opencode): use commands/ directory (plural) to match OpenCode docs

OpenCode documentation (https://opencode.ai/docs/commands/) uses
.opencode/commands/ (plural) as the canonical command directory.
The OpenCode runtime supports both .opencode/command/ and
.opencode/commands/ via a {command,commands} glob, but the
singular form was the original convention and is now outdated.

Update the OpenCode integration to write to .opencode/commands/
instead of .opencode/command/, aligning with the documented
standard and the OpenSpec fix (Fission-AI/OpenSpec#748).

Signed-off-by: Marcus Burghardt <maburgha@redhat.com>
Assisted-by: OpenCode (claude-opus-4-6)

* feat(registrar): add legacy_dir fallback for backward-compatible directory migration

Add _resolve_agent_dir() to CommandRegistrar that checks a
legacy_dir fallback when the canonical directory does not exist.
When legacy_dir is found, a deprecation warning directs users to
run "specify integration upgrade" to migrate.

The OpenCode integration declares legacy_dir: ".opencode/command"
so that extension and preset registration, as well as command
cleanup, continue working for projects that have not yet migrated
to .opencode/commands/.

The legacy_dir mechanism is opt-in: integrations that do not
declare it get no fallback and no behavioral change.

Add end-to-end test verifying that "specify integration upgrade
opencode" migrates commands from legacy .opencode/command/ to
canonical .opencode/commands/ and removes stale files.

Signed-off-by: Marcus Burghardt <maburgha@redhat.com>
Assisted-by: OpenCode (claude-opus-4-6)

* fix(registrar): address PR review feedback on legacy_dir handling

- Fix deprecation warning formatting: quote paths and remove trailing
  '/.' that produced confusing '.opencode/commands/.' output
- Eliminate duplicate warnings: pass pre-resolved directory to
  register_commands() via _resolved_dir parameter so
  _resolve_agent_dir() is only called once per agent
- Fix unregister_commands() to clean both canonical and legacy dirs
  when both exist, preventing orphaned command files after upgrade
- Add test_unregister_cleans_legacy_when_both_dirs_exist regression
  test and tighten warning count assertion to exactly 1

Assisted-by: OpenCode (claude-opus-4-6)
Signed-off-by: Marcus Burghardt <maburgha@redhat.com>

---------

Signed-off-by: Marcus Burghardt <maburgha@redhat.com>

tests/integrations/test_integration_subcommand.py

@@ -762,7 +762,7 @@ class TestIntegrationSwitch:
         assert result.exit_code == 0, result.output
 
         # Git extension commands should exist for opencode
-        opencode_git_feature = project / ".opencode" / "command" / "speckit.git.feature.md"
+        opencode_git_feature = project / ".opencode" / "commands" / "speckit.git.feature.md"
         assert opencode_git_feature.exists(), "Git extension command should exist for opencode"
 
         # Old kimi extension skills should be removed
@@ -837,7 +837,7 @@ class TestIntegrationSwitch:
         ])
         assert result.exit_code == 0, result.output
 
-        opencode_git_feature = project / ".opencode" / "command" / "speckit.git.feature.md"
+        opencode_git_feature = project / ".opencode" / "commands" / "speckit.git.feature.md"
         assert opencode_git_feature.exists(), "Git extension command should exist for opencode"
         assert not copilot_git_feature.exists(), "Old Copilot extension skill should be removed"
 
@@ -858,7 +858,7 @@ class TestIntegrationSwitch:
         result = _run_in_project(project, ["extension", "disable", "git"])
         assert result.exit_code == 0, result.output
 
-        opencode_git_feature = project / ".opencode" / "command" / "speckit.git.feature.md"
+        opencode_git_feature = project / ".opencode" / "commands" / "speckit.git.feature.md"
         assert opencode_git_feature.exists(), "Disabled extension command remains until integration switch"
 
         result = _run_in_project(project, [
@@ -1168,6 +1168,49 @@ class TestIntegrationUpgrade:
         assert data["integration"] == "gemini"
         assert "/speckit.plan" in template.read_text(encoding="utf-8")
 
+    def test_upgrade_migrates_opencode_legacy_dir(self, tmp_path):
+        """Upgrade moves OpenCode commands from .opencode/command/ to .opencode/commands/."""
+        project = _init_project(tmp_path, "opencode")
+
+        # Simulate a legacy project: rename commands/ back to command/
+        canonical = project / ".opencode" / "commands"
+        legacy = project / ".opencode" / "command"
+        assert canonical.is_dir(), "init should have created .opencode/commands/"
+        canonical.rename(legacy)
+        assert legacy.is_dir()
+        assert not canonical.exists()
+
+        # Patch the manifest to reflect old paths (command/ not commands/)
+        manifest_path = project / ".specify" / "integrations" / "opencode.manifest.json"
+        manifest_data = json.loads(manifest_path.read_text(encoding="utf-8"))
+        patched_files = {}
+        for path, info in manifest_data.get("files", {}).items():
+            patched_files[path.replace(".opencode/commands/", ".opencode/command/")] = info
+        manifest_data["files"] = patched_files
+        manifest_path.write_text(json.dumps(manifest_data), encoding="utf-8")
+
+        old_commands = sorted(legacy.glob("speckit.*.md"))
+        assert len(old_commands) > 0, "Legacy dir should have speckit command files"
+
+        result = _run_in_project(project, [
+            "integration", "upgrade", "opencode",
+            "--script", "sh",
+            "--force",
+        ])
+        assert result.exit_code == 0, f"upgrade failed: {result.output}"
+
+        # New commands in canonical dir
+        assert canonical.is_dir(), ".opencode/commands/ should exist after upgrade"
+        new_commands = sorted(canonical.glob("speckit.*.md"))
+        assert len(new_commands) > 0, "Commands should exist in .opencode/commands/"
+
+        # Stale files removed from legacy dir
+        remaining = list(legacy.glob("speckit.*.md"))
+        assert len(remaining) == 0, (
+            f"Legacy .opencode/command/ should have no speckit files after upgrade, "
+            f"found: {[f.name for f in remaining]}"
+        )
+
 
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