feat: implement POS tag sync with C++ upstream (closes #40)

- Add tree-sitter based script to extract POS tags from C++ source
- Add Makefile targets: sync-postypes, check-postypes
- Update postype.go with tags from Kiwi v0.23.2
- Add new tags: POS_P, POS_PV, POS_PA, POS_PV_I, POS_PA_I
- Remove non-existent tags: POS_V, POS_VV_R, POS_VA_R, POS_VX_R, POS_XSA_R
- Fix naming: POS_USER_0 -> POS_USER0 (match C++ enum)

Author: mrchypark

Makefile

@@ -25,3 +25,23 @@ format:
 	# go install mvdan.cc/gofumpt@latest
 	gofumpt -l -w .
 
+.PHONY: sync-postypes
+sync-postypes:
+	@echo "Extracting POS tags from Kiwi $(KIWI_VERSION)..."
+	source .venv/bin/activate && python scripts/extract_postags.py $(KIWI_VERSION)
+	@echo "Generated postype_generated.go"
+	@echo "Comparing with current postype.go..."
+	@diff -u postype.go postype_generated.go || true
+	@echo "To apply changes, run: mv postype_generated.go postype.go"
+
+.PHONY: check-postypes
+check-postypes:
+	@source .venv/bin/activate && python scripts/extract_postags.py $(KIWI_VERSION)
+	@if diff -q postype.go postype_generated.go > /dev/null 2>&1; then \
+		echo "POS types are in sync with Kiwi $(KIWI_VERSION)"; \
+	else \
+		echo "POS types are OUT OF SYNC with Kiwi $(KIWI_VERSION)"; \
+		echo "Run 'make sync-postypes' to update"; \
+		exit 1; \
+	fi
+