Concrete StateStorage + host-intel read-back (ADR-0008)

[filipeforattini]

What to build

Provide a concrete StateStorage backend (cookies + storage + service-worker state, no longer a no-op) and read back persisted host intel when the Crawler builds a session — making the memory available without auto-priming yet. Foundation for the StealthProfile. See ADR-0008.

Acceptance criteria

• A concrete StateStorage backend persists and loads session state.
• Host intel is read back at session build (available, not yet auto-applied).
• Tests cover state round-trip and host-intel read-back.

Blocked by

• Crawl registry + crawl list (ADR-0007) #65