Add XIC v1 Engine — Execute-In-Compressed Runtime Integration

- Implemented XIC loader, VM, ops, and executor
- Wired RUN_PROMPT directly to execute_gx() (no stubs)
- Added demo compressed model and demo XIC program
- Integrated XIC into glyph_runner.py with --xic flag and shell support
- Added full validation suite and XIC_INTEGRATION_REPORT.md
- Verified real GSZ3 decompression and execution pipeline

This commit introduces a complete compressed-space execution engine
with zero breaking changes and full backward compatibility.

xic_vm.py

@@ -0,0 +1,30 @@
+from xic_loader import XICProgram
+from xic_ops import XICContext, OP_TABLE
+
+
+class XICRuntimeError(Exception):
+    pass
+
+
+def run_xic_program(prog: XICProgram) -> XICContext:
+    """Execute an XIC program.
+
+    Creates a context, iterates through instructions, dispatches
+    each operation to the handler in OP_TABLE, and returns the final context.
+    """
+    ctx = XICContext()
+
+    for i, instr in enumerate(prog.instructions):
+        op_name = instr.op
+
+        if op_name not in OP_TABLE:
+            raise XICRuntimeError(f"Unknown operation at instruction {i}: {op_name}")
+
+        op_handler = OP_TABLE[op_name]
+
+        try:
+            op_handler(ctx, *instr.args)
+        except Exception as e:
+            raise XICRuntimeError(f"Operation {op_name} failed at instruction {i}: {e}")
+
+    return ctx