refactor: unify bundle-symlink scripts into setup_bundle_symlinks.py

The three per-version setup_*_bundle_symlinks.py scripts were logically
identical, differing only in the version string.  Replace the duplicated
logic with a single parameterised script:

  tools/linux/setup_bundle_symlinks.py <version>

The three named scripts are kept as one-liner thin wrappers that forward
to the unified script, preserving backwards compatibility.

tools/linux/setup_bundle_symlinks.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+"""Creates symlinks in versions/<VERSION>-bundle to mirror vendor directory structure.
+
+Usage:
+    python3 setup_bundle_symlinks.py <version>
+
+Example:
+    python3 setup_bundle_symlinks.py 25.01
+    python3 setup_bundle_symlinks.py 26.00
+    python3 setup_bundle_symlinks.py 26.01
+"""
+import os
+import sys
+from pathlib import Path
+
+if len(sys.argv) != 2:
+    print(f"Usage: {sys.argv[0]} <version>", file=sys.stderr)
+    sys.exit(1)
+
+version = sys.argv[1]
+
+ROOT = Path(__file__).resolve().parents[2]
+bundle_root = ROOT / f"versions/{version}-bundle"
+vendor_root = ROOT / f"versions/{version}"
+
+if not vendor_root.exists():
+    print(f"Error: vendor directory not found: {vendor_root}", file=sys.stderr)
+    sys.exit(1)
+if not bundle_root.exists():
+    print(f"Error: bundle directory not found: {bundle_root}", file=sys.stderr)
+    sys.exit(1)
+
+bundle_7zip = bundle_root / "CPP/7zip"
+vendor_7zip = vendor_root / "CPP/7zip"
+bundle_cpp  = bundle_root / "CPP"
+vendor_cpp  = vendor_root / "CPP"
+
+# Root-level symlinks: C and Asm
+for name in ("C", "Asm"):
+    target = bundle_root / name
+    if not target.exists() and not target.is_symlink():
+        rel = os.path.relpath(vendor_root / name, bundle_root)
+        os.symlink(rel, target)
+        print(f"  symlink: {target.relative_to(ROOT)} -> {rel}")
+
+for item in vendor_7zip.iterdir():
+    target = bundle_7zip / item.name
+    if not target.exists() and not target.is_symlink():
+        rel = os.path.relpath(item, bundle_7zip)
+        os.symlink(rel, target)
+        print(f"  symlink: {target.relative_to(ROOT)} -> {rel}")
+
+bundle_ui = bundle_7zip / "UI"
+vendor_ui = vendor_7zip / "UI"
+bundle_ui.mkdir(exist_ok=True)
+for item in vendor_ui.iterdir():
+    target = bundle_ui / item.name
+    if not target.exists() and not target.is_symlink():
+        rel = os.path.relpath(item, bundle_ui)
+        os.symlink(rel, target)
+        print(f"  symlink: {target.relative_to(ROOT)} -> {rel}")
+
+for item in vendor_cpp.iterdir():
+    if item.name == "7zip":
+        continue
+    target = bundle_cpp / item.name
+    if not target.exists() and not target.is_symlink():
+        rel = os.path.relpath(item, bundle_cpp)
+        os.symlink(rel, target)
+        print(f"  symlink: {target.relative_to(ROOT)} -> {rel}")
+
+print("Done")