v0.26.2 - doctor action queues and migration listing fixes

v0.26.2 is a patch release that fixes the remaining GitHub issue
queue for migration listing, doctor actionability, and session-start
maintenance prompts.

Added

• Added pk-doctor actionability metadata. Each doctor finding now
  includes action_required, action_kind, default_agent_action,
  requires_user_confirmation, and acceptable_resolution, with
  aggregate action_totals surfaced alongside severity totals. This
  prevents actionable INFO findings from disappearing behind a clean
  0 WARN gate. Closes #43.
• Added pk-resume action-queue guidance. Status briefings now treat
  severity and actionability as separate queues, require dispositions
  for actionable doctor findings, and require explicit apply/reject/
  inspect/defer decisions for pending or in-progress migrations. Closes
  #44.
• Imported the expanded skill catalog from the current aibox sync.
  The dogfood tree now includes the generated data-ai, design, devops,
  documents, engineering, and product skill families plus corresponding
  command adapters.

Fixed

• Fixed lazy gateway serialization for empty structured list
  results. Catalog-backed gateway tools now preserve FastMCP
  structured output and return a text fallback when the unstructured
  content list would otherwise be empty. This keeps
  list_migrations(state="pending") valid when no Migration entities
  exist or when non-entity Markdown briefings sit in pending/. Closes
  #42.
• Resolved and archived generated migration records. The invalid
  processkit/runtime migrations from the aibox sync were rejected with
  integrity reasons, the runtime drift migration was applied by
  preserving local edits, and all three terminal migration entities were
  archived via context-archiving.

Verification

• python3 -m py_compile context/skills/_lib/processkit/gateway/lazy.py context/skills/_lib/processkit/gateway/registry.py src/context/skills/_lib/processkit/gateway/lazy.py src/context/skills/_lib/processkit/gateway/registry.py
• uv run --with mcp --with pyyaml --with jsonschema --with httpx --with sqlite-vec --with pytest pytest context/skills/processkit/processkit-gateway/scripts/test_gateway.py context/skills/processkit/migration-management/scripts/test_migration_management.py -q
• uv run --with mcp --with pyyaml --with jsonschema --with httpx --with sqlite-vec --with pytest pytest src/context/skills/processkit/processkit-gateway/scripts/test_gateway.py src/context/skills/processkit/migration-management/scripts/test_migration_management.py -q
• python3 -m py_compile context/skills/processkit/pk-doctor/scripts/doctor.py context/skills/processkit/pk-doctor/scripts/checks/common.py context/skills/processkit/pk-doctor/mcp/server.py src/context/skills/processkit/pk-doctor/scripts/doctor.py src/context/skills/processkit/pk-doctor/scripts/checks/common.py src/context/skills/processkit/pk-doctor/mcp/server.py
• uv run context/skills/processkit/pk-doctor/scripts/test_pk_doctor_json.py
• uv run context/skills/processkit/pk-doctor/scripts/test_doctor.py
• uv run src/context/skills/processkit/pk-doctor/scripts/test_pk_doctor_json.py
• uv run src/context/skills/processkit/pk-doctor/scripts/test_doctor.py
• uv run scripts/smoke-test-servers.py

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