Split the public banner URL from the runner-internal clone URL

Every auto-published page, in all three pipelines, carried a source link to
`localhost:3005`. The template was never at fault — it links `{{{source}}}`
verbatim; the bad URL was baked into each page's wikitext by the publisher.

Root cause was one variable serving two incompatible purposes. `URL_TO_GITEA`
has to be an address the runner container can clone from, and since the runner
uses host networking that is `http://localhost:3005`. All three workflows then
composed `GITEA_REPO_URL` — the base of the public banner link, written into
the wiki for anyone to read — out of that same loopback value.

Adds a second org variable, `PUBLIC_URL_TO_GITEA`, for the public base
(`https://git.novoyuuparosk.org`), and points the banner at it. Cloning keeps
using `URL_TO_GITEA`. The two are now documented as deliberately separate,
because collapsing them looks like tidying up.

`lib/wiki.public_source_base()` validates the banner base rather than trusting
it: unset, relative, loopback, mDNS (`*.local`) or private-range values raise
with the variable to set. A misconfiguration that would publish an unreachable
link now stops the run instead. Note the failure mode this creates on purpose:
until `PUBLIC_URL_TO_GITEA` exists, publishing aborts rather than proceeding
with a wrong URL.

Also builds the source path with `rel.as_posix()`, so the separator in a URL
does not depend on the OS the publisher runs on — it produced backslashes when
the renderer was exercised on Windows.

Prerequisites before this can publish:

1. Add the org variable `PUBLIC_URL_TO_GITEA` = https://git.novoyuuparosk.org
2. Flush the act_runner callee cache — `docker compose up -d --force-recreate
   act_runner`. Per the cross-cutting decisions log, edits to `publish-*.yml`
   keep executing the stale cached copy, and this change is in those files.

Pages already published still carry the old URL in their stored wikitext. They
are only corrected by re-publishing each pipeline in full.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -72,7 +72,10 @@ Secrets and variables are scoped to the `novoyuuparosk-wiki` org, inherited by a
 **Variables:**
 - `WIKI_BASE_URL` = `https://wiki.novoyuuparosk.org`
 - `WIKI_API_URL` = `https://wiki.novoyuuparosk.org/api.php`
-- `URL_TO_GITEA` = Gitea instance base URL (e.g. `http://localhost:3005`). Named with `URL_TO_` prefix — Gitea blocks variable names starting with `GITEA_` or `GITHUB_`.
+- `URL_TO_GITEA` = **runner-internal** Gitea base URL, used only for cloning (e.g. `http://localhost:3005` — the runner uses host networking). Named with `URL_TO_` prefix — Gitea blocks variable names starting with `GITEA_` or `GITHUB_`.
+- `PUBLIC_URL_TO_GITEA` = **public** Gitea base URL (`https://git.novoyuuparosk.org`), used only for the source link in each published page's banner.
+
+These two must stay separate. `URL_TO_GITEA` is a loopback address, so composing the banner from it published every page — across all three pipelines — citing `localhost:3005`, which resolves for nobody reading the wiki. `lib/wiki.public_source_base()` now rejects a loopback, mDNS, or private-range value, so that misconfiguration fails the run instead of reaching a page.
 
 ## Branch naming
 
@@ -98,6 +101,8 @@ Secrets and variables are scoped to the `novoyuuparosk-wiki` org, inherited by a
 | MediaWiki API path | `api.php` (classic action API) | 2026-06-09 |
 | Branch naming (this repo) | `automation/<pipeline>` for pipeline-development branches | 2026-06-09 |
 | Variable naming | `URL_TO_GITEA` not `GITEA_URL` — Gitea blocks `GITEA_`/`GITHUB_` prefixes | 2026-06-09 |
+| **Clone URL ≠ banner URL** | Split into `URL_TO_GITEA` (runner-internal, for cloning) and `PUBLIC_URL_TO_GITEA` (public, for the page banner). One variable served both, and since host networking forces the clone address to `localhost:3005`, every auto-published page in every pipeline cited a link no reader could open. The banner value is validated by `public_source_base()` — loopback, mDNS and private-range addresses abort the run. Pages published before this carry the bad URL in their wikitext and need a full re-publish per pipeline to clear | 2026-09-09 |
+| Source URL separators | `rel.as_posix()` in the banner URL, so the path separator never depends on the OS the publisher happens to run on | 2026-09-09 |
 | Columns shorthand | Side-by-side columns authored as a ` ```columns ` fenced block, expanded post-Pandoc in shared `lib/wiki.py` (universal across pipelines). No wiki template or PHP extension — runs Pi-side before the API call | 2026-06-14 |
 
 Per-pipeline decisions live in each pipeline's README.
@@ -113,6 +118,7 @@ Via the Gitea web UI logged in as `mikkeli` (an owner of `novoyuuparosk-wiki`):
   - [x] `WIKI_BASE_URL`
   - [x] `WIKI_API_URL`
   - [x] `URL_TO_GITEA`
+  - [ ] `PUBLIC_URL_TO_GITEA` = `https://git.novoyuuparosk.org` — **required**; the publishers abort without it
 
 With Pi access: