feat: add contact UI helpers and path editor for routing management

- Implemented contactTypeIcon and contactTypeColor functions for better UI representation of contact types.
- Created colorForName and firstCharacterOrEmoji functions to enhance contact display.
- Developed PathEditorSheet widget for managing contact paths with a user-friendly interface.
- Introduced RoutingSheet for managing contact routing modes and displaying path history.
- Added a script for generating proof of concept (PoC) payloads for clipboard contact import validation.

scripts/security/contact_import_clipboard_pocs.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+"""Generate local PoCs for MeshCore clipboard contact import validation gaps.
+
+The output is a meshcore:// URI suitable for manual testing in a local/dev app
+session. It does not connect to BLE/USB/TCP devices or transmit anything.
+"""
+
+from __future__ import annotations
+
+import argparse
+import sys
+
+
+SCHEME = "meshcore://"
+
+
+def uri_from_bytes(payload: bytes) -> str:
+    return SCHEME + payload.hex()
+
+
+def oversized_payload(size: int) -> bytes:
+    if size < 1:
+        raise ValueError("size must be positive")
+    return b"A" * size
+
+
+def short_malformed_payload() -> bytes:
+    return b"\x00"
+
+
+def non_advert_like_payload() -> bytes:
+    # 98 bytes matches the UI's minimum exported-contact length check, but the
+    # content is intentionally not a valid signed advert/contact packet.
+    payload = bytearray(98)
+    payload[0:4] = b"POC!"
+    payload[36] = 0xFF
+    payload[-4:] = b"END!"
+    return bytes(payload)
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(
+        description="Generate meshcore:// clipboard import PoC payloads."
+    )
+    parser.add_argument(
+        "case",
+        choices=("short", "non-advert", "oversized"),
+        help="PoC case to generate.",
+    )
+    parser.add_argument(
+        "--size",
+        type=int,
+        default=4096,
+        help="Byte length for the oversized case. Default: 4096.",
+    )
+    args = parser.parse_args()
+
+    if args.case == "short":
+        payload = short_malformed_payload()
+    elif args.case == "non-advert":
+        payload = non_advert_like_payload()
+    else:
+        payload = oversized_payload(args.size)
+
+    sys.stdout.write(uri_from_bytes(payload))
+    sys.stdout.write("\n")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())