refactor(runtime): extract active compact facts

[xuruiray]

Summary

• extract the active-full compact summary fact engine into active-full-compact-facts.ts
• keep the existing public summary builders as compatibility delegates
• enforce the one-way boundary with a source extraction contract test

Refs #1084

This is the active-full-compact.ts fact-extraction checkbox only. It is flat off current main and does not depend on #1258.

Behavior

Behavior- and visually-neutral. The regexes, filtering order, stable serialization, budgets, fallback text, optional-field drop order, and public exports are preserved.

Validation

• npm test --workspace @maka/runtime — 2265 passed, 7 skipped, 0 failed
• npm run typecheck — passed
• npm run lint — passed
• touched-file Biome format check — passed
• git diff --check — passed
• npm test — all feature-relevant workspaces passed; parallel runner reported runtime-host and CLI failures
• isolated npm test --workspace @maka/runtime-host — 45/45 passed

Known independent baseline

On this flat-off-main branch, npm test --workspace maka-agent is 629/631: the two failures are the exact node:sqlite stderr pollution tracked in #1257 and fixed independently by #1258. This PR intentionally does not stack that fix.

[Astro-Han]

No concrete findings. The extraction preserves the fact-builder behavior and public delegation, and CI is green.