A single invalid resource template breaks the whole resources/templates/list response

[ramalama]

Problem

AbilityRegistry::addAbility() accepts any ResourceTemplateInterface without
validation. The resources/templates/list handler converts all registered
templates via ListResourceTemplatesResult::fromResponseData(), and the SDK's
ResourceTemplate::validate() throws an InvalidArgumentException when name
or uriTemplate is empty.

Because the exception is thrown while building the complete result, one
misbehaving plugin template turns every resources/templates/list request into
a JSON-RPC -32603 internal error — all valid templates from other plugins
become undiscoverable as well.

Steps to reproduce

1. Register a template whose getName() or getUriTemplate() returns ''
   (e.g. via a plugin subscribing to InitialiseMCPServerEvent).
2. Call resources/templates/list.
3. The whole request fails with -32603 instead of listing the remaining
   valid templates.

Proposal

Preferred: validate abilities up front in AbilityRegistry::addAbility() and
reject invalid ones there (fail fast, at registration time, attributable to the
offending plugin — ideally with a log entry naming it).

Alternative/minimal: catch the per-entry InvalidArgumentException in the
handler, skip the broken template and log a warning, so one bad plugin cannot
take down discovery for everyone.

Notes

The same "one bad ability poisons the shared list" pattern applies to
tools/list and resources/list since they now also build typed results —
worth fixing consistently, which speaks for the registration-time validation.