Add context action for rich single-call resource fetching

[titouanmathis]

Implements #69 — adds a context action to servers and sites resources.

Changes

Core

• Added context to ACTIONS constant

MCP

• New handleServerContext() — fetches server + 6 sub-resources in parallel
• New handleSiteContext() — fetches site + 4 sub-resources in parallel (deployments limited to last 5)
• Wired into existing handleServers and handleSites handlers
• Added context to READ_ACTIONS
• Updated help and schema handlers
• Comprehensive test coverage

Usage

{"resource": "servers", "action": "context", "id": "725393"}

Returns:

{
  "server": { ... },
  "sites": [ ... ],
  "databases": [ ... ],
  "database_users": [ ... ],
  "daemons": [ ... ],
  "firewall_rules": [ ... ],
  "scheduled_jobs": [ ... ]
}

Closes #69

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.82%. Comparing base (d3c0f6f) to head (6e58afd).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #71   +/-   ##
=======================================
  Coverage   99.82%   99.82%           
=======================================
  Files         218      219    +1     
  Lines        3462     3487   +25     
  Branches      799      807    +8     
=======================================
+ Hits         3456     3481   +25     
  Misses          6        6           

Flag	Coverage Δ
unittests	99.82% <100.00%> (+<0.01%)	⬆️

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