Fix install + admin bugs reported in issue #169

Addresses the five bugs found on master (6e139a1b) during a fresh
Docker install and admin testing:

1. Missing `details` column in gold_fin_log (HTTP 500 on finishing
   construction with gold, buying Gold Club, admin giving gold):
   - Add `details varchar(255)` to the gold_fin_log schema, matching
     every INSERT and the a2b2.php reader that already use it.
   - Fix the broken positional INSERT in Logging::goldFinLog() (it sent
     3 values for a 7-column table) which 500'd on the same gold path.

2. Admin "View Player Info" fatal error: `<? php` -> `<?php` in
   Admin/Templates/playerinfo.tpl.

3. "Reset Server" leaving the DB corrupted (Duplicate key name
   'idx_ft_bonus_xy'): move the croppers indexes inline into the
   CREATE TABLE IF NOT EXISTS so structure recreation is idempotent,
   and add `croppers` to the reset truncate list.

4. Install wizard crash on failed DB connection (mysqli_error(false)):
   use mysqli_connect_error() and show a friendly, actionable message
   (incl. the Docker "db" hostname hint).

5. PHP exposing errors/stack traces to end users: ship a production
   php.ini baseline + docker/php/zz-travianz.ini that turns off
   display_errors and logs to stderr instead.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker/php/zz-travianz.ini

@@ -0,0 +1,11 @@
+; TravianZ production PHP settings
+; -----------------------------------------------------------------------------
+; Do NOT show PHP errors, warnings or stack traces to end users. Leaking server
+; paths and internal structure is both a security risk and makes the game look
+; unstable. Errors are still logged server-side (visible via `docker logs`).
+display_errors = Off
+display_startup_errors = Off
+log_errors = On
+error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT & ~E_NOTICE & ~E_WARNING
+; Send the error log to the container's stderr so it shows up in `docker logs web`.
+error_log = /dev/stderr