Clean repo for open source release

Remove build artifacts, dev tool configs, unused dependencies,
and third-party source dumps. Add proper README, update .gitignore,
clean up Makefile.

src/main/java/com/tiedup/remake/cells/CellState.java

@@ -0,0 +1,33 @@
+package com.tiedup.remake.cells;
+
+/**
+ * State of a Cell System V2 cell.
+ *
+ * INTACT     — all walls present, fully operational.
+ * BREACHED   — some walls broken, prisoners may escape.
+ * COMPROMISED — Core destroyed or too many walls broken; cell is non-functional.
+ */
+public enum CellState {
+    INTACT("intact"),
+    BREACHED("breached"),
+    COMPROMISED("compromised");
+
+    private final String serializedName;
+
+    CellState(String serializedName) {
+        this.serializedName = serializedName;
+    }
+
+    public String getSerializedName() {
+        return serializedName;
+    }
+
+    public static CellState fromString(String name) {
+        for (CellState state : values()) {
+            if (state.serializedName.equalsIgnoreCase(name)) {
+                return state;
+            }
+        }
+        return INTACT;
+    }
+}