fix: add grok-build to should_compile_agents_md and update dispatch test

- Add 'grok-build' to should_compile_agents_md() so compiling for
  grok-build correctly produces AGENTS.md output
- Add 'agents_grok-build', 'commands_grok-build', 'instructions_grok-build'
  to the expected bucket keys in test_partition_parity_with_old_buckets,
  reflecting the new target registered in this PR

Co-authored-by: sergio-sisternes-epam <207026618+sergio-sisternes-epam@users.noreply.github.com>

Author: Copilot

src/apm_cli/core/target_detection.py

@@ -242,7 +242,7 @@ def should_compile_agents_md(target: CompileTargetType) -> bool:
     """Check if AGENTS.md should be compiled.
 
     AGENTS.md is generated for vscode, cursor, opencode, codex, gemini,
-    windsurf, kiro, antigravity, hermes, all, and minimal targets.
+    windsurf, kiro, antigravity, grok-build, hermes, all, and minimal targets.
     Gemini needs it because GEMINI.md imports AGENTS.md.
 
     Args:
@@ -261,6 +261,7 @@ def should_compile_agents_md(target: CompileTargetType) -> bool:
         "codex",
         "gemini",
         "antigravity",
+        "grok-build",
         "windsurf",
         "kiro",
         "hermes",

tests/unit/integration/test_data_driven_dispatch.py

@@ -326,6 +326,9 @@ def test_partition_parity_with_old_buckets(self):
             "rules_claude",  # was instructions_claude, aliased
             "skills",  # cross-target bucket
             "hooks",  # cross-target bucket
+            "agents_grok-build",
+            "commands_grok-build",
+            "instructions_grok-build",
             "prompts_copilot-app",  # copilot-app uses dedicated prompts bucket
             "canvas_copilot",  # canvas extensions (copilot-only, experimental)
         }