chore: Release server.json schema version 2025-12-11 (#841)

Prepared by Claude Code, iterated and reviewed by me.

## Summary

This PR releases the server.json schema version `2025-12-11`,
incorporating URL template variables for remote servers from #570.

### What's New

- **URL Template Variables for Remote Servers** - Remote servers can now
define configurable variables in URLs using `{curly_braces}` notation,
enabling multi-tenant deployments.

### Schema Version
- `2025-10-17` → `2025-12-11`

## Release Sequence

1. ~~**First: Merge static repo PR** -
https://github.com/modelcontextprotocol/static/pull/11 (publishes schema
to versioned URL)~~
2. **Then: Merge this PR** - Updates registry code to reference the new
schema version

## Changes in This PR

- [x] Update CHANGELOG.md with release notes
- [x] Update `CurrentSchemaVersion` in `pkg/model/constants.go`
- [x] Update schema example URL in `docs/reference/api/openapi.yaml`
- [x] Update schema URL in `pkg/api/v0/types.go`
- [x] Update all documentation examples to use new schema version
- [x] Regenerate `server.schema.json`

## Test Plan
- [x] `make check` passes (lint, schema validation, example validation)
- [x] Unit tests pass for validators and publisher commands

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

pkg/api/v0/types.go

@@ -32,7 +32,7 @@ type ServerMeta struct {
 }
 
 type ServerJSON struct {
-	Schema      string            `json:"$schema" required:"true" minLength:"1" format:"uri" doc:"JSON Schema URI for this server.json format" example:"https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json"`
+	Schema      string            `json:"$schema" required:"true" minLength:"1" format:"uri" doc:"JSON Schema URI for this server.json format" example:"https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json"`
 	Name        string            `json:"name" minLength:"3" maxLength:"200" pattern:"^[a-zA-Z0-9.-]+/[a-zA-Z0-9._-]+$" doc:"Server name in reverse-DNS format. Must contain exactly one forward slash separating namespace from server name." example:"io.github.user/weather"`
 	Description string            `json:"description" minLength:"1" maxLength:"100" doc:"Clear human-readable explanation of server functionality." example:"MCP server providing weather data and forecasts via OpenWeatherMap API"`
 	Title       string            `json:"title,omitempty" minLength:"1" maxLength:"100" doc:"Optional human-readable title or display name for the MCP server." example:"Weather API"`

pkg/model/constants.go

@@ -36,7 +36,7 @@ const (
 // Schema versions
 const (
 	// CurrentSchemaVersion is the current supported schema version date
-	CurrentSchemaVersion = "2025-10-17"
+	CurrentSchemaVersion = "2025-12-11"
 	// CurrentSchemaURL is the full URL to the current schema
 	CurrentSchemaURL = "https://static.modelcontextprotocol.io/schemas/" + CurrentSchemaVersion + "/server.schema.json"
 )