Extract mcp-server to its own repo (meshtastic/meshtastic-mcp) (#10861)

The Python MCP server + hardware test harness that lived under mcp-server/
now has its own home at https://github.com/meshtastic/meshtastic-mcp
(published, versioned independently). Remove the in-tree copy and wire the
firmware repo to the standalone server externally.

- Delete mcp-server/ (96 files) and the 8 harness-coupled AI workflow files
  under .claude/commands/ and .github/prompts/ that drove ./mcp-server/
  run-tests.sh — those workflows now ship with meshtastic-mcp as skills.
- .mcp.json: register the server via
  `uvx --from git+https://github.com/meshtastic/meshtastic-mcp meshtastic-mcp`
  instead of a local ./mcp-server/.venv, keeping MESHTASTIC_FIRMWARE_ROOT="."
  so the MCP tools still work from this checkout with no local build.
- Repoint the remaining references (AGENTS.md, CLAUDE.md,
  .github/copilot-instructions.md, bin/regen-*.sh, docs, Screen.h,
  userPrefs.jsonc, test/fixtures/nodedb/README.md, .trunk/configs/.bandit)
  at the standalone repo. The MCP tool surface is unchanged — only the
  pytest harness moves out; run it from a meshtastic-mcp checkout with
  MESHTASTIC_FIRMWARE_ROOT pointed here.

No build/CI/platformio coupling existed, so nothing in the firmware build
changes.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

bin/regen-fake-nodedbs.sh

@@ -22,9 +22,10 @@ if [[ ! -d bin/_generated/meshtastic ]]; then
 fi
 
 # 2) Pick a Python interpreter that has the meshtastic deps installed.
-#    Prefer the mcp-server venv (most likely to be set up by the operator).
+#    Prefer a local venv; otherwise fall back to system python3 (install the
+#    `meshtastic` package there, or run this under `uv run --with meshtastic`).
 PY="python3"
-for cand in mcp-server/.venv/bin/python3 .venv/bin/python3; do
+for cand in .venv/bin/python3; do
     if [[ -x "$cand" ]]; then
         PY="$cand"
         break
@@ -70,4 +71,5 @@ echo "Done. To load on Portduino native:"
 echo "  cp build/fixtures/nodedb/nodes_v25_1000.proto ~/.portduino/default/prefs/nodes.proto"
 echo ""
 echo "To push to a hardware device:"
-echo "  Use the mcp-server tool: push_fake_nodedb(size=1000, target=\"hardware\", port=\"/dev/cu.usbmodemXXXX\", confirm=True)"
+echo "  Use the meshtastic-mcp tool: push_fake_nodedb(size=1000, target=\"hardware\", port=\"/dev/cu.usbmodemXXXX\", confirm=True)"
+echo "  (MCP server: https://github.com/meshtastic/meshtastic-mcp)"