fix(everything): remove dead code in resource template URI validation and subscription cleanup

[1060996408]

Description

Two small dead-code removals in src/everything's resource layer. No behavioral change. 95 / 95 tests still pass.

Server Details

• Server: everything (reference server)
• Changes to: resources

Motivation and Context

Two unreachable branches in the resource handlers were doing more harm than good — once misread, they suggest invariants that don't actually hold.

resources/templates.ts — parseResourceId

The guard

if (uri.toString().startsWith(textUriBase) && uri.toString().startsWith(blobUriBase)) {
  throw new Error(uriError);
}

is dead. textUriBase and blobUriBase are mutually exclusive prefixes, so the && is never true. The SDK's template-based routing already guarantees the URI prefix is one of the two before the handler runs, so the surrounding "unknown URI" error path can't trigger either. Reduced to the only check that still does work — resourceId must be a positive integer.

resources/subscriptions.ts — sendSimulatedResourceUpdates

if (subscribers.has(sessionId)) {
  await server.server.notification(...);
} else {
  subscribers.delete(sessionId); // subscriber has disconnected
}

The else deletes sessionId from subscribers whenever the session isn't in one specific URI's subscriber set. The comment claims the session has disconnected, but that doesn't follow: a session subscribed to URI A but not URI B will hit the else for URI B every iteration. And Set.delete of an absent element is a no-op, so the branch never had useful effect. Removed.

How Has This Been Tested?

• npm test in src/everything: 95 / 95 pass
• Spot-checked the everything server with an LLM client (Claude Code) — read-resource, subscribe / unsubscribe flows, and template-routed text/{id} and blob/{id} reads all behave as before.

Breaking Changes

None.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature
• Breaking change
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follow MCP security best practices
• I have updated the server's README accordingly (no user-facing change)
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options (none changed)

Additional context

• 1 commit, 2 files (subscriptions.ts, templates.ts), +19 / −27 lines.
• No new dependencies, no API surface change.