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>

CLAUDE.md

@@ -2,12 +2,12 @@
 
 > **TL;DR**
 >
-> |                |                                                                    |
-> | -------------- | ------------------------------------------------------------------ |
-> | Local tests    | `./bin/run-tests.sh` (exit 0 GREEN · 1 RED · 2 AMBER · 3 FILTERED) |
-> | Hardware tests | `./mcp-server/run-tests.sh`                                        |
-> | Format         | `trunk fmt`                                                        |
-> | Mirror docs    | `.github/copilot-instructions.md` (canonical) · `AGENTS.md`        |
+> |                |                                                                                                                        |
+> | -------------- | ---------------------------------------------------------------------------------------------------------------------- |
+> | Local tests    | `./bin/run-tests.sh` (exit 0 GREEN · 1 RED · 2 AMBER · 3 FILTERED)                                                     |
+> | Hardware tests | [meshtastic/meshtastic-mcp](https://github.com/meshtastic/meshtastic-mcp) (`MESHTASTIC_FIRMWARE_ROOT` → this checkout) |
+> | Format         | `trunk fmt`                                                                                                            |
+> | Mirror docs    | `.github/copilot-instructions.md` (canonical) · `AGENTS.md`                                                            |
 >
 > **Need this? It's here.**
 >