Reframe the interface around composed posts, not republished entries

The channel publishes a post written from a hall entry -- condensed,
personal, reach-optimized -- not the entry itself. That changes what
this interface is for and where its boundary sits.

Composition is deliberately outside the interface. Composing is a
probabilistic editorial task, and Blueprint 48.1 forbids an LLM in the
mandatory request path, so an interface that composed on demand would be
non-deterministic exactly where determinism is the whole claim. It is
also editorial: a post speaks about a named person's work in
HelixForge's voice, and a review step inside the request path is a
review step nobody performs.

The contract now takes a composed post with a required reviewer, a cited
source entry and a consent basis. A post carrying none of those is
refused. Absence of objection is not consent, and in an audit trail an
unfaithful post looks exactly like a faithful one -- the defence is that
a human read it, the source is named, and both are recorded.

The first experiment is rebuilt accordingly. The old competition asked
how to fit a whole entry into Telegram; that question no longer exists.
The new one asks whether the portrait earns the 3072 characters of
caption limit it costs, which is a delivery question this interface
actually owns. Competition over editorial voice belongs to the campaign
and runs on the per-variant engagement this interface reports.

Adds T05b (composition and review), T05c (consent basis for the 94
existing participants, blocking public publication) and T11 (extracting
the campaign into pr-hall-of-helix).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014KmVxhJ35tCo7rE7UnLwWu

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 1116572@bnt-lap001
Assistant-Session: 8ba9bb93-a72a-4883-b189-2499cce5c400

experiments/E-tg-delivery.yaml

@@ -0,0 +1,68 @@
+# The interface's first experiment: does the portrait earn its place?
+#
+# This tests DELIVERY, which this interface owns. The competition about which
+# editorial voice travels belongs to the campaign and is run on the per-variant
+# engagement this interface reports — see docs/observation.md.
+#
+#   fluid experiment design --file experiments/E-tg-delivery.yaml
+#   fluid experiment start E-tg-delivery --generation 2 \
+#     --default-revision R-2 --policy-out rp.json
+#   fluid policy put --file rp.json
+fluid_experiment:
+  schema_version: "0.1"
+
+  id: "E-tg-delivery"
+  interface_id: "helix-forge-telegram-publishing"
+
+  hypothesis_refs:
+    - "H-tg-visual"
+    - "H-tg-textonly"
+
+  # R-2 attaches the portrait, R-3 publishes text only. Neither is an
+  # incumbent: R-1 publishes without either treatment being settled, so this
+  # is a comparison between two answers rather than against a baseline.
+  control_revision: "R-2"
+  candidate_revisions:
+    - "R-3"
+
+  cohorts:
+    - "telegram-subscribers"
+
+  allocation:
+    control: 0.5
+    candidate: 0.5
+
+  # An even split because there is no incumbent to protect. The usual 90/10
+  # caution limits exposure to an unproven candidate; here both arms are
+  # equally unproven and the scarce resource is posts, not safety.
+
+  metrics:
+    primary:
+      - "engagement_rate"
+    guardrails:
+      - "unreviewed_publication"
+      - "missing_source_attribution"
+      - "missing_subject_consent"
+      - "error_rate"
+    secondary:
+      - "source_link_rate"
+      - "forward_rate"
+    learning:
+      - "time_to_first_view"
+
+  start_conditions:
+    - "both revisions verified against the private test channel"
+    - "channel has at least 100 subscribers"
+
+  stop_conditions:
+    - "hard_guardrail_violation"
+    - "unreviewed_publication"
+    - "manual_stop"
+    - "max_duration_reached"
+
+  max_duration_hours: 2160  # 90 days
+
+  result:
+    state: "PLANNED"
+    preferred_revision: null
+    evidence_refs: []

experiments/E-tg-length.yaml

@@ -1,68 +0,0 @@
-# The first live experiment: which presentation serves readers better.
-#
-# Do not start this until the private test channel has confirmed both forms
-# render correctly, and the public channel has enough subscribers for the
-# result to mean anything. The intent (section 12) is explicit that an
-# underpowered window should report INCONCLUSIVE rather than be shortened.
-#
-#   fluid experiment design --file experiments/E-tg-length.yaml
-#   fluid experiment start E-tg-length --generation 2 \
-#     --default-revision R-2 --policy-out rp.json
-#   fluid policy put --file rp.json
-fluid_experiment:
-  schema_version: "0.1"
-
-  id: "E-tg-length"
-  interface_id: "helix-forge-telegram-publishing"
-
-  hypothesis_refs:
-    - "H-tg-teaser"
-    - "H-tg-serial"
-
-  # R-2 implements the teaser form, R-3 the serialized form. Neither is the
-  # control in the usual sense: R-1 cannot publish a long entry at all, so
-  # this is a comparison between two answers rather than against a baseline.
-  control_revision: "R-2"
-  candidate_revisions:
-    - "R-3"
-
-  cohorts:
-    - "telegram-subscribers"
-
-  allocation:
-    control: 0.5
-    candidate: 0.5
-
-  # An even split because there is no incumbent to protect. The usual 90/10
-  # caution exists to limit exposure to an unproven candidate; here both arms
-  # are equally unproven and the scarce resource is entries, not safety.
-
-  metrics:
-    primary:
-      - "read_through_rate"
-    guardrails:
-      - "entry_content_loss"
-      - "error_rate"
-      - "messages_per_entry"
-    secondary:
-      - "reaction_rate"
-      - "forward_rate"
-    learning:
-      - "time_to_first_read"
-
-  start_conditions:
-    - "both revisions verified against the private test channel"
-    - "channel has at least 100 subscribers"
-
-  stop_conditions:
-    - "hard_guardrail_violation"
-    - "entry_content_loss"
-    - "manual_stop"
-    - "max_duration_reached"
-
-  max_duration_hours: 2160  # 90 days: roughly 12 entries at current cadence
-
-  result:
-    state: "PLANNED"
-    preferred_revision: null
-    evidence_refs: []