feat(monitors): Add monitor catalog tools

[dcramer]

Add catalog-only cron monitor tools so agents can discover monitors and inspect schedule, environment state, recent check-ins, and aggregate stats without expanding the default direct tool surface.

Agent-Facing Monitor Tools

find_monitors supports organization-level monitor discovery with project, environment, owner, query, and limit filters. get_monitor_details bundles monitor metadata, recent check-ins, and stats into one agent-friendly response, using projectSlugOrId when a monitor needs project scoping.

Sentry Endpoint Handling

The API client uses upstream-confirmed monitor list, detail, check-in, and stats routes. Check-ins keep Sentry's statsPeriod/start/end date range params, while stats translate the agent-facing time range to since/until/resolution for StatsMixin.

Catalog-Only Routing

get_sentry_resource can resolve monitor URLs through get_monitor_details, but only when that catalog tool is available. Generated definitions confirm the direct tool surface remains unchanged.

[sentry-warden]

get_sentry_resource inputSchema always exposes 'monitor' resourceType even in skill contexts where it will always fail

The resourceType enum in get_sentry_resource statically includes "monitor" in the tools/list inputSchema for all skill sessions, but the handler calls assertCatalogToolAvailable(context, "get_monitor_details", ...) which throws a UserInputError whenever get_monitor_details is absent — which is the case for all seer, triage, and preprod sessions. The context-aware description omits monitor in those contexts, but the schema still advertises it as a valid enum value; clients that enumerate enum members to decide valid calls will find a value that always errors in those sessions.

Evidence

• get_sentry_resource declares skills: ["inspect", "triage", "seer", "preprod"] (get-sentry-resource.ts:510), while get_monitor_details declares skills: ["inspect"] only (get-monitor-details.ts:72).
• The resourceType z.enum in get-sentry-resource.ts always includes "monitor", and getFilteredInputSchema in availability.ts only removes constraint-bound params, not conditional enum values — so the wire inputSchema always shows "monitor" regardless of active skill.
• At execution time, the "monitor" switch arm unconditionally calls assertCatalogToolAvailable(context, "get_monitor_details", "Monitor") (get-sentry-resource.ts:735), which throws UserInputError whenever availableToolNames does not contain get_monitor_details.
• The description function conditionally omits monitor from the examples and resource-ID list when monitorResourcesAvailable is false (get-sentry-resource.ts:514-517), confirming the intent is context-dependent, but the schema is not adjusted to match.

_{Identified by Warden mcp-audit}