feat(feedback): disclose session sharing in the /feedback acknowledgement

The /feedback acknowledgement now echoes the receiving session id and
reports the mounted telemetry backend's sharing policy: the telemetry seam
exposes a backend-independent TelemetrySharingStatus through a required
abstract sharing member on the Telemetry service, the OTel backend maps its
mode onto it, and the command appends one policy-only sharing sentence
(full / feedback-only / disabled / not configured) to the acknowledgement.
The web client renders the text through the existing command row without a
client change; a new assembled-browser e2e mounts the shipped telemetry row
in FULL mode against a local dead endpoint and pins the shipped default
sentence as a keyless golden.

packages/session/session-telemetry/README.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 packages/session/session-telemetry/README.md
-README.md: 827554dd53a81eab5a5fd7f145df3f835db9c173
-README.zh.md: a350ea5935a2143cb0f876eeb1eb0520ffee5c53
+README.md: 707dcfcdb0c8dfbd622630351928ac43562535ec
+README.zh.md: bd080adceebf83cd9e53d72a7093db376cf6cbd1