canon(classification): add the publication category, standard v1.1

Implements CUST-WP-0070-T01.

New §5.7 publication: repos whose purpose is to publish and keep a body of
authored content for readers, where the corpus itself is the deliverable. It is
durable, unlike project — a published record is kept, not resolved and retired.
Disambiguated against research (which asks what we need to understand), product,
and tooling (a wiki engine is tooling; the corpus it serves is a publication).

Added to the §5 allowed values, the §11 decision procedure, the §16 agent
prompt, and allowed.yaml. history and participation join the
knowledge_and_evidence capability family so hall-of-helix's tags do not warn.

Version 1.1, not 2.0: §17 previously read any allowed-value change as major.
This addition is purely additive — no existing classification becomes invalid,
and neither validator enforces a version match, so the 125 repo files declaring
1.0 keep validating. §17 now distinguishes adding a permitted value (minor) from
removing or renaming one (major), rather than leaving the rule contradicted.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SQ6oF1DtVDKcD1FCpvRVLx

canon/standards/repo-classification.allowed.yaml

@@ -9,7 +9,7 @@
 # to match the standard version. CUST-WP-0050 T01.
 
 standard: "Repo Classification Standard"
-version: "1.0"
+version: "1.1"
 canon_id: "canon-repo-classification"
 
 # category — exactly 1 required (§5)
@@ -20,6 +20,7 @@ categories:
   - tooling
   - product
   - business
+  - publication
 
 # domain / secondary_domains — primary exactly 1; secondaries 0..n (§6)
 domains:
@@ -81,6 +82,8 @@ capability_families:
     - traceability
     - documentation
     - decision-support
+    - history
+    - participation
   platform_and_operations:
     - platform
     - deployment