feat: add audit log entries tool

[nbouvrette]

Related issues

This addresses a gap in the current MCP tool surface — the audit log API is already in the OpenAPI spec and has Speakeasy naming hints in schemas/suggestions.yaml, but is not exposed as an MCP tool.

Describe the solution you've provided

Adds a single entry to schemas/mcp-enable-tools.yaml to enable the GET /api/v2/auditlog endpoint as a read-only MCP tool (get-audit-log-entries).

The tool description includes practical guidance for AI agents:

• Resource specifier syntax for querying flag change history (proj/<projectKey>:env/<envKey>:flag/<flagKey>)
• Pagination pattern using before/after Unix epoch timestamps
• Response limit behavior (max 20 entries per call, newest-first)

Note: This PR only contains the overlay change. Since the codebase is generated by Speakeasy and external contributors cannot run speakeasy run against the LaunchDarkly registry, the generated output (funcs, tools, models, server registration) will need to be produced by the maintainers.

Describe alternatives you've considered

Context window optimization

Adding more tools increases the MCP context window footprint for all users, even those who don't need audit log access. The existing --tool flag allows whitelisting specific tools, but there's no easy way to exclude a single tool without listing all the others.

A few ideas worth considering (as a separate effort):

1. --exclude-tool flag — inverse of --tool, letting users opt out of specific tools without listing everything else.
2. Tool groups (e.g. --tool-group flags, --tool-group audit-log, --tool-group ai-configs) — would let users selectively load categories of tools. This would be especially valuable since AI Configs alone accounts for 11 of the 20 current tools.
3. Documenting --tool and --scope — these existing flags aren't mentioned in the README. Simply documenting them would help users who want to reduce context window usage today.

Additional context

• The audit log endpoint is already present in schemas/openapi.json with operationId getAuditLogEntries
• schemas/suggestions.yaml already defines x-speakeasy-group: auditLog and x-speakeasy-name-override: listEntries for this endpoint
• The tool is scoped as read-only