feat(projects): support 'active' filter on browse_projects (GitLab 18.5+)

[polaz]

👍 React to this issue if you need this feature — helps us prioritise.

Problem

GitLab 18.5 added an active query parameter to GET /projects (and /groups) that returns only non-archived AND non-pending-delete entries in a single shot. Without it, clients have to fetch then filter on the client side — slower and prone to off-by-one with pagination.

Investigation done (current state)

Verified against src/entities/core/:

• ✅ browse_projects action list exists with various filters
• ❌ No grep hit for project-level active filter passing — only smart-user-search.ts:110 uses active: true but for users, not projects
• ❌ No tier/version gating helper for "≥18.5" specifically

Re-verify before coding:

grep -rn 'active.*=.*true\|active: true' src/entities/core/

Acceptance criteria

• New optional active?: boolean param on browse_projects list action schema
• Sends active=true or active=false to GitLab when set
• Version-gated via existing ConnectionManager.isFeatureAvailable — fallback to client-side filter on instances < 18.5
• Action description mentions "requires GitLab 18.5+" but works with degraded perf on older
• Integration test verifying both paths (mock version or skip via tier-gate helper)

GitLab API

• Endpoint: GET /api/v4/projects?active=true|false
• Tier: Free
• Version: 18.5+
• Docs: https://docs.gitlab.com/api/projects/

Estimate

2h

Context

Found during GitLab 18→19 API landscape analysis. Quality-of-life improvement that also offloads filtering work from the LLM context.