[Feature Request] Lazy-load command descriptions — only pre-load auto-trigger skill descriptions at session start

Currently, all installed skill and command descriptions are injected into the system prompt at session start, regardless of type. This is wasteful for explicitly-invoked commands (e.g. gsd:*, paul:*) which are never auto-triggered — their descriptions serve no purpose in the pre-loaded index.

Proposed change

Distinguish between:

• Auto-trigger skills (~/.claude/skills/) — descriptions pre-loaded at session start (current behavior, justified)
• Explicit commands (~/.claude/commands/) — only a name registry loaded at session start; full description/content loaded on invocation

Impact

Users with large framework installs (e.g. GSD + PAUL = ~60 commands) are paying unnecessary context cost every session. At scale this is a meaningful reduction in available context window.

Current behavior

All ~80+ skill and command descriptions are loaded unconditionally at session start, consuming context tokens even for commands that will never be auto-triggered and are only ever invoked explicitly via /command-name.