Add segment coverage ledger and mid-project plan for Crusader decompilation

- Created `crusader_segment_coverage_ledger.csv` to track segment coverage status, types, and known functions.
- Introduced `plan-mid.md` as a mid-project tracker outlining progress, objectives, and implementation priorities for the decompilation effort.
- Added scripts in `pyghidra_plans` to assist with instruction window dumping and reference inspection for the object at `0x4588`.
- Implemented functionality to scan for instruction uses of specific targets related to the decompilation project.

pyghidra_plans/scan_4588_instruction_uses.py

@@ -0,0 +1,17 @@
+TARGET_HEX = ("4588", "458a")
+
+listing = program.getListing()
+function_manager = program.getFunctionManager()
+
+instruction = listing.getInstructions(True)
+
+while instruction.hasNext():
+    insn = instruction.next()
+    text = insn.toString().lower()
+    if not any(token in text for token in TARGET_HEX):
+        continue
+
+    address = insn.getAddress()
+    function = function_manager.getFunctionContaining(address)
+    function_name = function.getName() if function is not None else "<no function>"
+    print(f"{address} {function_name} {insn}")