cleanup(cli): remove the profile-json config entry

`./.dsh-tmp-profile/config.json` was the web config-tree boot's user-config
plane, but never gained a writer: no production code created or edited it, no
test exercised it, and no user documentation named it. The fields it mapped
have owners elsewhere — provider/model are the api-gateway's default route and
persistenceRoot is an assembly fact, while typed user preferences live in
$DSH_HOME/settings.yaml.

Delete PROFILE_DIR, PROFILE_FILE, ProfileMapping, PROFILE_MAPPINGS, and
readProfile() with the patch source that consumed them. AppCLIEntry now
composes patches from CLI flags and the resolved frontend distIndex only; the
surrounding layers are unchanged. A file on disk is ignored completely — no
migration, replacement format, or deprecation diagnostic, per the pre-release
stance.

docs/user/guide/config.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/user/guide/config.md
-config.md: 0e2e0e7e7077adcacfaada1d038a0b1e63fcc0cd
-config.zh.md: 850a841286fe77db9169738b0b155f008205a1a8
+config.md: 6f656b573490a08ec893f4d14b487e6082015049
+config.zh.md: d4bb30023df46845ea720f3e6a45184479df0e72