MCP platform server scaffolding

[cstns]

Description

Lays the groundwork for the MCP platform tools server. No functional endpoint yet, just the wiring so subsequent PRs have somewhere to land.

• Adds @modelcontextprotocol/sdk and zod as dependencies
• Registers expertPlatformAutomation feature flag, same gate as expertAssistant (AI + expert enabled)
• Reorganizes forge/ee/routes/mcp/: renames existing registration routes to registrations.js, adds empty server.js shell, new index.js router wires both up
• Route shell at POST /api/v1/mcp returns 501 for now, gates on feature flag, rejects non-user tokens
• Existing registration endpoints (/api/v1/teams/:teamId/mcp/*) are unchanged

Related Issue(s)

closes #7426

Checklist

• I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production
• Link to Changelog Entry PR, or note why one is not needed.

Labels

• Includes a DB migration? -> add the area:migration label

[codecov]

Codecov Report

❌ Patch coverage is 21.67488% with 318 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.35%. Comparing base (0c9b327) to head (12a7179).

Files with missing lines	Patch %	Lines
forge/ee/lib/mcp/tools/applications.js	0.00%	50 Missing ⚠️
forge/ee/lib/mcp/tools/snapshots.js	0.00%	40 Missing ⚠️
forge/comms/platformAutomation.js	23.52%	39 Missing ⚠️
forge/ee/lib/mcp/tools/devices.js	0.00%	35 Missing ⚠️
forge/ee/lib/mcp/toolLoader.js	0.00%	30 Missing ⚠️
forge/comms/commsClient.js	0.00%	29 Missing ⚠️
forge/ee/lib/mcp/tools/instances.js	0.00%	28 Missing ⚠️
forge/ee/lib/mcp/tools/navigation.js	0.00%	16 Missing ⚠️
forge/ee/routes/mcp/registrations.js	78.12%	14 Missing ⚠️
forge/ee/lib/mcp/tools/platform.js	0.00%	13 Missing ⚠️
... and 4 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7596      +/-   ##
==========================================
- Coverage   76.29%   75.35%   -0.94%     
==========================================
  Files         414      425      +11     
  Lines       22167    22487     +320     
  Branches     5870     5930      +60     
==========================================
+ Hits        16912    16945      +33     
- Misses       5255     5542     +287     

Flag	Coverage Δ
backend	75.35% <21.67%> (-0.94%)	⬇️

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[n-lark]

looks good to me

[cstns]

we'll be removing this once child branches are merged down, as 3rd party access is not a priority at the moment

[andypalmi]

We tested it thoroughly together during today's online meeting and fixed issues we saw together, so I am quite confident to give it the green light

[andypalmi]

@cstns Let's update the PR description with all of the changes before merging please