docs: finish the whole-file-diff sweep across comments and RFCs

Codex's stale-prose pass found seven more spots still describing the
result diff as ALWAYS an applied contextual hunk, or a create/binary
overwrite as rendering "only the call-time card": the DiffCallView JSDoc
and the acp bridge diff-arm comment, the FsWriteOutcome.before and
readTextForDiff JSDoc, and three RFC lines. All now say: the result diff
is the applied change — a contextual hunk when there is a before-image,
else a whole-file diff (create / undiffable binary) — and a successful
mutation always returns the result diff so the model-facing text can't
clobber it. Regenerate the cordis catalog (source line shift).

packages/core/tools/src/index.ts

@@ -159,8 +159,9 @@ export interface TerminalCallView {
  * A call that creates or modifies files, rendered as an inline diff card by a
  * capable UI. Set by a tool whose call writes/edits a file (e.g. `write`,
  * `edit`). The diffs are derived from the call ARGUMENTS (a create's `oldText` is
- * `null`); the result-time applied-hunk diff (with context) is a separate
- * {@link DiffResultView} the tool emits after `execute`.
+ * `null`); the tool emits a separate {@link DiffResultView} after `execute` — the
+ * applied change (an edit/overwrite hunk with context, or a whole-file diff for a
+ * create).
  */
 export interface DiffCallView {
   card: 'diff'