refactor: move outlier functions to semantically correct files

[Copilot]

Automated semantic clustering of 811 functions across 14 packages identified 3 misplaced functions and 1 over-broad file. This PR moves each to where a developer would naturally look for it.

Changes

• mcp/errors.go → mcp/connection_logging.go: ConnectionErrorContext + LogConnectionError belonged with the other connection diagnostic helpers (logReconnectStart, logOutboundRPCRequest, etc.), not in a file conventionally reserved for error type definitions. errors.go deleted.

• config/config_tracing.go → new config/validation_tracing.go: validateOpenTelemetryConfig and its 4 W3C regex patterns extracted into a dedicated validation file, consistent with the existing validation*.go convention in this package.

• mcp/tool_result.go → mcp/collaborator_permission.go: LogAndWrapCollaboratorPermission moved alongside ParseCollaboratorPermissionArgs — all collaborator permission logic now co-located.

• server/http_helpers.go → split into server/middleware.go: Middleware composition (wrapWithMiddleware, applyIfConfigured, WithOTELTracing, buildMCPHandler, WithSDKLogging, mcpHandlerConfig) extracted into a dedicated file; request/response utilities remain in http_helpers.go.

No logic changes — pure file reorganization.

[Copilot]

Pull request overview

Refactors code layout by relocating a few “outlier” helpers into files whose names and responsibilities better match their semantics (server middleware composition, MCP connection diagnostics, tracing validation, collaborator permission helpers), without changing behavior.

Changes:

• Extracts MCP HTTP middleware composition + OTEL/SDK logging wrappers into internal/server/middleware.go, leaving request/response utilities in http_helpers.go.
• Moves MCP connection failure diagnostic types/helpers into internal/mcp/connection_logging.go and deletes the now-redundant errors.go.
• Extracts OpenTelemetry validation into internal/config/validation_tracing.go and co-locates collaborator permission logging with its argument parsing helper.

Show a summary per file

File	Description
internal/server/middleware.go	New file containing MCP handler construction and standard middleware stack (OTEL/auth/HMAC/shutdown/SDK logging).
internal/server/http_helpers.go	Removes middleware-related code, keeping only HTTP helper utilities.
internal/mcp/tool_result.go	Removes collaborator-permission logging/wrapping helper from tool result utilities.
internal/mcp/errors.go	Deletes file after relocating the only remaining connection-diagnostic helpers.
internal/mcp/connection_logging.go	Adds connection failure diagnostic context + logging helpers alongside other connection logging.
internal/mcp/collaborator_permission.go	Adds LogAndWrapCollaboratorPermission next to collaborator permission arg parsing.
internal/config/validation_tracing.go	New validation file for OpenTelemetry config (W3C ID regex + endpoint rules).
internal/config/config_tracing.go	Removes embedded validation/regex; keeps tracing config + variable expansion/default registration.

Copilot's findings

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• Files reviewed: 8/8 changed files
• Comments generated: 0

[lpcox]

@copilot merge main

[Copilot]

@copilot merge main

Done — merged main into the branch (c108941). There was one conflict in internal/server/http_helpers.go where main had kept the middleware functions we moved to middleware.go; resolved by keeping our split. Also forward-ported main's gen_ai semantic conventions change (replacing attribute.String("session.id", …) / "gateway.tag" with tracing.GenAIConversationID / tracing.GatewayTag) into middleware.go. All checks pass.