[somdoron]

SUB-1333 moved the Idempotency-Key ledger into SQLite, and sessions and blueprints already lived there. But the --session-store-dir help, the volume-guard reasons, several book pages, and scripts/idempotency-smoke.sh still described the file-backed ledger and treated the session directory as live storage.

• The help and the settings reference now describe session_store_dir and blueprint_dir as one-time import sources that move to archive/.
• The session-store guard rules give the real risks. The nested-volume rule stays because the import archives the whole directory.
• "Run the server" points readers at database_path and says to back up its directory, including the WAL file, while the server is stopped.
• The smoke script reads keyed run evidence from SQLite and keeps all of its state in its temp directory. Before this, it wrote into ~/.submilli/server/db.

Fixes SUB-1745

🤖 Generated with Claude Code

Main integration preserves the unified volume directory layout and refreshes existing AI-assisted authorship hashes. The smoke check now installs a temporary local package before Blueprint validation, removes it to test pre-dispatch failure, and checks the current runs schema, disconnect handling, and retained evidence after session deletion. Same-repository source links are checked against the checkout to avoid the observed GitHub 503 failures; missing-link fixtures remain enforced.

Validation: Rust formatting, workspace Clippy, shell syntax, and the normal idempotency smoke checks passed using local mock HTTP only. Ten smoke cases passed; the optional slow waiter check was not run, and the unwritable-ledger case remains covered by existing in-process fault tests. Independent clean-code, correctness, and edge-case review completed, including focused review of the final smoke adjustment. Current-head CI is running.

Analytics impact: none; factual storage wording and build-time checks do not change routes, forms, tracking hooks, or event contracts.

After deployment: PR author verifies the updated storage reference pages. Existing authorship labels are preserved; human editorial requirements still apply before publication.