A component can name the files its build reads elsewhere

Freshness compared the commits under a component's own cwd, which is
right about where its files are and wrong about what its build reads.
tdep-survey's two clients each source one shared scripts/android-sdk-env.sh:
a fix committed there changed what every build does, moved no component's
subtree head, rebuilt nothing, and left every card correctly reporting
"current" while answering a narrower question than the reader was asking.

alsoWatch names the rest. The paths join the component's own in the same
subtree-head and dirty comparisons -- git takes several pathspecs, so it
stays one call each -- and it is part of the acceptance gate like any
other declared field. Declared rather than inferred: which files a build
reads is not knowable from here, and both wrong guesses are expensive.

Raised by the tdep-survey session, which traced why its dioxus client
could never become stale on the serving host.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

server/src/service.rs

@@ -398,6 +398,7 @@ mod tests {
             build: Command::default(),
             cwd: None,
             stale_when: None,
+            also_watch: Vec::new(),
             service,
             built_from: None,
         }