refactor(core): unify accepted note runtime boundaries

[phernandez]

Why

Accepted-note create, update, and edit could be composed from partial persistence helpers, preparation instantiated the full EntityService graph, and hosted runtime code depended on cloud/local implementation packages instead of neutral core owners.

What

• add one complete accepted-note snapshot persistence operation for entity content, graph rows, and search state
• keep move persistence explicitly narrower so path changes do not replace the graph
• extract immutable preparation values and lightweight preparation functions with explicit dependencies
• move accepted-note repository/search cleanup values and shared runtime contracts to neutral packages
• retain thin compatibility exports for downstream transition
• document and enforce the resulting dependency direction

Verification

• focused accepted-note, preparation, route, and architecture tests: 84 passed
• SQLite pre-materialization atomicity regression: passed
• targeted Postgres create/update/edit/move routes: 9 passed
• just fast-check
• just doctor
• just package-check

Companion

Hosted imports and composition are updated in basicmachines-co/basic-memory-cloud#1548, pinned to this core commit.

Closes #1096
Closes #1097
Closes #1098