Play Framework

chore: clarify scaffold comment — conf is source of truth, DSL is escape hatch (PF-90)

User feedback: the previous comment confusingly suggested that http.port
\"should\" be specified in build.gradle.kts. Reframed so:

1. conf/application.conf is unambiguously the source of truth for
   http.port / https.port / application.secret / db / etc.
2. DSL properties (httpPort.set(...), playId.set(...)) are positioned
   as escape hatches for build-time overrides — useful but not the
   normal place to configure these values.
3. -P task-time overrides (-PhttpPort=8080, -PplayId=staging) are
   shown as the most-ephemeral form for one-off runs without editing
   any file.

Mirrors the precedence chain we built earlier: conf → DSL → -P, with
each level overriding the previous. The new comment makes that
explicit instead of treating the DSL as the canonical config site.