docs(cloud-agents): align 'untracked files' precision with caution

The "Prefer `repo` over `file`" rule said `repo` entries pick up
"tracked changes plus untracked files" while the security caution
right below said "tracked changes plus untracked, non-gitignored
files". The caution is the accurate one (matches
`git ls-files --others --exclude-standard` in
`app/src/ai/agent_sdk/driver/snapshot.rs::build_repo_patch`), so
tighten the rule to match.

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: hongyi-chen

src/content/docs/agent-platform/cloud-agents/handoff/snapshots.mdx

@@ -66,7 +66,7 @@ Each line has exactly these fields:
 A few rules to follow when writing declarations:
 
 * **Paths must be absolute.** Relative paths are rejected and logged as malformed.
-* **Prefer `repo` over `file` for paths inside a repository.** Warp generates a git diff for each `repo` entry (tracked changes plus untracked files), so individual `file` entries inside that repo are redundant and dropped before upload. Including a `repo` entry is also more extensible than enumerating files.
+* **Prefer `repo` over `file` for paths inside a repository.** Warp generates a git diff for each `repo` entry (tracked changes plus untracked, non-gitignored files), so individual `file` entries inside that repo are redundant and dropped before upload. Including a `repo` entry is also more extensible than enumerating files.
 * **Repos are diffed, not copied wholesale.** Only changed files are uploaded for each `repo` entry, so listing a large repository is cheap when the agent's changes are small.
 * **`file` entries are for paths outside any declared repo** — for example, logs the agent wrote to `/tmp` or scratch files in `$HOME`.