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.

scripts/type-equiv.manifest.json

@@ -1620,6 +1620,11 @@
       "symbol": "WebBootGraph",
       "source": "packages/client/modules/src/client/manifest.ts"
     },
+    {
+      "doc": "docs/subsystems/telemetry.md",
+      "symbol": "TelemetrySharingStatus",
+      "source": "packages/session/session-telemetry/src/index.ts"
+    },
     {
       "doc": "docs/subsystems/telemetry.md",
       "symbol": "TelemetrySeverity",