Add progressive orientation discovery

[jlrickert]

Summary

• make aggregate orientation a compact discovery index with KEG title, summary, effective role, source, and flight cap while withholding KEG instructions
• extend keg_settings with ordered, multi-KEG minimal retrieval grouped into one batch request per compatible Hub
• add older-Hub fallbacks for discovery and targeted settings without reintroducing aggregate instructions
• document summary as concise discovery text and instructions as targeted operational guidance, then refresh rendered integration artifacts

Why

Aggregate orientation currently loads every covered KEG's operational instructions up front. That increases latency and token use before an agent has identified which KEGs are relevant. This change keeps session flight selection immutable and moves KEG-specific instructions behind an explicit targeted settings request.

Behavior

• compatible remote Hubs use GET /api/v1/orient once per Hub for compact discovery
• keg_settings accepts mutually exclusive keg and kegs; batches are limited to 100 canonical references and minimal mode
• minimal=false continues to return the complete config for exactly one KEG
• batch detail requests preserve input order and group references by Hub
• older Hubs fall back to existing catalog and config reads
• aggregate orientation retains flight instructions but never includes KEG instructions, including under full_access
• ordinary MCP tools receive no flight override

The corresponding Tapper Hub endpoints and hosted catalog integration are a coordinated follow-up change.

Validation

• go test ./... -count=1
• go test -race ./pkg/mcp ./pkg/tapper
• task lint:docs
• task render-integrations
• go test ./pkg/tapper ./pkg/mcp ./pkg/integrations/... ./pkg/parity/...
• git diff --check