ci: make PR validation trigger unconditional (remove paths filter)

The pr-pipeline workflow filtered both push and pull_request on
paths (**.prose.md, scripts/**.sh, **.yaml, **.yml). A PR whose diff
touched none of those paths — e.g. PR #77, deliverables/-only —
produced no Gitea Actions run at all, so validate/lint/ai-review and
the merge gate were silently skipped.

Remove the paths filter from both triggers and record in the file
that the trigger is intentionally unfiltered. No job, step, needs,
if or command is changed.

.gitea/workflows/pr-pipeline.yaml

@@ -1,19 +1,18 @@
 name: PR Pipeline — Authorize → Validate → Review → Merge
+# TRIGGER IS INTENTIONALLY UNFILTERED — DO NOT RE-ADD A `paths:` FILTER.
+#
+# This workflow previously carried `paths: ['**.prose.md', 'scripts/**.sh',
+# '**.yaml', '**.yml']` on both `push` and `pull_request`. Any PR whose diff
+# touched none of those patterns (for example a `deliverables/`-only PR, or a
+# `scripts/*.py` / `bin/*` change) therefore produced NO Gitea Actions run at
+# all: validation, lint, ai-review and the merge gate were silently skipped.
+# Validation must run for every pull request and every push to master, so the
+# trigger is deliberately unconditional.
 on:
   push:
     branches: [master]
-    paths:
-      - '**.prose.md'
-      - 'scripts/**.sh'
-      - '**.yaml'
-      - '**.yml'
   pull_request:
     types: [opened, synchronize, reopened]
-    paths:
-      - '**.prose.md'
-      - 'scripts/**.sh'
-      - '**.yaml'
-      - '**.yml'
 
 jobs:
   auth: