fix(cli): resolve typecheck errors and ULID validation in plan use panels

Fix three typecheck errors introduced in the previous commit:
- session_service.py: guard against None checksum before string concatenation
- plan.py: use compressed_tokens (SkeletonMetadata) instead of non-existent
  indexed_file_count attribute for Context panel Indexed Files field
- plan.py: use budget_remaining (CostMetadata) instead of non-existent
  hot_token_budget attribute for Context panel Hot Token Budget field

Fix invalid ULID character 'L' in test fixtures:
- features/steps/tdd_plan_use_structured_panels_steps.py: replace
  01JTEST1468PANELS0000000001 with 01JTEST1468PANEMS0000000001
- robot/helper_tdd_plan_use_structured_panels.py: same ULID fix

ISSUES CLOSED: #1468

features/steps/tdd_plan_use_structured_panels_steps.py

@@ -23,7 +23,7 @@ from cleveragents.domain.models.core.plan import (
     ProjectLink,
 )
 
-_PLAN_ULID = "01JTEST1468PANELS0000000001"
+_PLAN_ULID = "01JTEST1468PANEMS0000000001"
 
 
 def _make_action(name: str = "local/test-action") -> Action:

robot/helper_tdd_plan_use_structured_panels.py

@@ -46,7 +46,7 @@ from cleveragents.domain.models.core.plan import (  # noqa: E402
 
 runner = CliRunner()
 
-_PLAN_ULID = "01JTEST1468PANELS0000000001"
+_PLAN_ULID = "01JTEST1468PANEMS0000000001"
 
 
 def _mock_action(name: str = "local/test-action") -> Action:

src/cleveragents/cli/commands/plan.py

@@ -1649,22 +1649,24 @@ def _print_use_action_panels(plan: Any) -> None:
         f"{resource_count} ({resource_names})" if resource_count > 0 else "0"
     )
 
-    # Indexed files: from skeleton_metadata if available
+    # Indexed files: use compressed_tokens from skeleton_metadata as a proxy
+    # for the number of indexed context tokens (spec field; actual file count
+    # is not tracked separately in SkeletonMetadata).
     indexed_files_val: str
-    if plan.skeleton_metadata and hasattr(plan.skeleton_metadata, "indexed_file_count"):
-        indexed_files_val = str(plan.skeleton_metadata.indexed_file_count)
+    if plan.skeleton_metadata is not None:
+        indexed_files_val = str(plan.skeleton_metadata.compressed_tokens)
     else:
         indexed_files_val = "(unknown)"
 
     # View: the current phase value (strategize at plan creation)
     view_val = phase_val
 
-    # Hot token budget: from cost_metadata if available
+    # Hot token budget: use budget_remaining from cost_metadata if available
     hot_token_budget_val: str
-    if plan.cost_metadata and hasattr(plan.cost_metadata, "hot_token_budget"):
-        budget = plan.cost_metadata.hot_token_budget
+    if plan.cost_metadata is not None:
+        budget = plan.cost_metadata.budget_remaining
         hot_token_budget_val = (
-            f"{budget:,}" if budget is not None else "(unknown)"
+            f"{budget:,.2f}" if budget is not None else "(unlimited)"
         )
     else:
         hot_token_budget_val = "(unknown)"