feat(admin): add GET /admin/tool-requests for ops review

[JayZeeDesign]

What this does

Adds a super-admin read API for catalog tool requests so ops can review them without querying Postgres. GET /admin/tool-requests follows the same pattern as GET /admin/feedback:

• require_superadmin gate
• limit + before pagination (descending by id)
• Optional status (open|done|dismissed) and source (web|cli|mcp|claude-connector|api) filters
• Returns all triage fields: id, created_at, capability, query, note, contact, source, status, org_id, user_email

Does not change the public POST /tool-requests intake.

How it was tested

uv run --with pytest-xdist pytest -n auto -q tests/test_tool_requests.py tests/test_app_roles.py
# 24 passed

uv run lint-imports
# Contracts: 14 kept, 0 broken.

New tests cover:

• Auth requirement (403 for regular members)
• Listing recent filings with all expected fields
• Filtering by status and source
• Pagination with limit and before
• Validation of invalid filter values (400)

Checklist

• uv run --with pytest-xdist pytest -n auto -q passes locally
• Added or updated tests for the change (if it affects behavior)
• Updated the relevant docs/context/ fragment (if a subsystem changed)
• No secrets in the diff (keys, tokens, .env values)