Restore GDS dependency on finish target

No changes to the non do- versions of targets. bazel-orfs does
not use the finish target; it uses do-finish and can invoke
do-gds as a separate step.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

Author: oharboe

flow/Makefile

@@ -598,7 +598,8 @@ klayout_guides: $(RESULTS_DIR)/5_route.def $(OBJECTS_DIR)/klayout.lyt
 .PHONY: finish
 finish: $(LOG_DIR)/6_report.log \
         $(RESULTS_DIR)/6_final.v \
-        $(RESULTS_DIR)/6_final.sdc
+        $(RESULTS_DIR)/6_final.sdc \
+        $(GDS_FINAL_FILE)
 	$(UNSET_AND_MAKE) elapsed
 
 .PHONY: elapsed
@@ -650,7 +651,7 @@ clean_abstract:
 check-klayout:
 	@if [ -z "$(KLAYOUT_CMD)" ]; then \
 		echo "Error: KLayout not found. Install KLayout or set KLAYOUT_CMD."; \
-		echo "Hint: 'make finish' works without KLayout. Only GDS/DRC/LVS need it."; \
+		echo "Hint: KLayout is needed for GDS/DRC/LVS targets."; \
 		exit 1; \
 	fi
 

flow/docs/KLayoutOptionalDependency.md

@@ -9,7 +9,7 @@ without KLayout installed.
 
 | Target | Requires KLayout | Description |
 |---|---|---|
-| `make finish` | No | Complete flow through timing reports |
+| `make finish` | Yes | Complete flow including GDS generation |
 | `make gds` | Yes | Generate GDS/OAS from finished design |
 | `make drc` | Yes | Run DRC checks (requires GDS) |
 | `make lvs` | Yes | Run LVS checks (requires GDS) |
@@ -22,7 +22,7 @@ missing and a KLayout-dependent target is invoked:
 
 ```
 Error: KLayout not found. Install KLayout or set KLAYOUT_CMD.
-Hint: 'make finish' works without KLayout. Only GDS/DRC/LVS need it.
+Hint: KLayout is needed for GDS/DRC/LVS targets.
 ```
 
 ## bazel-orfs Integration