Every mutating tool now reports `previousSizeInBytes` and
`currentSizeInBytes`; `obsidian_append_to_note` gains the `created`
upsert flag. Agents can detect typo-pathed appends, accidental
whole-file clobbers, and concurrent-writer drift from the response
alone — no per-agent read-history state on the server.
- Added ObsidianService.tryGetSize / getSize (HEAD /vault/{path},
Content-Length, path-gated, retry-bypassed).
- Removed ObsidianService.noteExists (write_note overwrite check
migrated to tryGetSize !== null on the same HEAD).
- obsidian_delete_note elicit prompt includes file size before
confirmation.
- obsidian_append_to_note description front-loads create-if-missing
upsert branch.
- @biomejs/biome ^2.4.14 → ^2.4.15 (devDependency).
See changelog/3.1.x/3.1.7.md for the full release notes.