fix(production): fix multiple remote server errors from nginx logs

- Fix 413 Request Entity Too Large: bump client_max_body_size to 256M,
  PHP post_max_size/upload_max_filesize to 256M, fastcgi timeouts to 300s
- Fix missing v_smtp_active view: add IF NOT EXISTS to all CREATE VIEW
  statements in schema.sql for idempotent migrates
- Fix bars.svg 404: create animated SVG spinner in app/public/assets/img/
- Fix nginx rate limiting: increase admin zone from 60r/m (1 r/s) to
  300r/m (5 r/s) with burst=30 to handle ~11 concurrent HTMX fragment
  GETs on contenus.php page load
- Add deploy-nginx recipe to justfile for uploading nginx config to server
- Database readonly issue mitigated by existing --chown + deploy-server.sh
  permissions fix
- Add comprehensive PHP/JS debugging logs for settings checkboxes:
  per-field raw POST values in error_log, console.log on htmx:beforeSend,
  htmx:sendError, htmx:afterRequest, toast lifecycle
- Fix toast auto-remove script: use getElementById with unique ID instead
  of querySelector which could remove wrong toast on rapid clicks

app/storage/schema.sql

@@ -387,10 +387,10 @@ CREATE INDEX idx_thesis_tags_thesis ON thesis_tags(thesis_id);
 -- VIEWS
 -- ============================================================================
 
-CREATE VIEW v_smtp_active AS
+CREATE VIEW IF NOT EXISTS v_smtp_active AS
 SELECT * FROM smtp_settings WHERE id = 1;
 
-CREATE VIEW v_theses_full AS
+CREATE VIEW IF NOT EXISTS v_theses_full AS
 SELECT
     t.id,
     t.identifier,
@@ -450,7 +450,7 @@ LEFT JOIN thesis_tags tt ON t.id = tt.thesis_id
 LEFT JOIN tags tg ON tt.tag_id = tg.id
 GROUP BY t.id;
 
-CREATE VIEW v_theses_public AS
+CREATE VIEW IF NOT EXISTS v_theses_public AS
 SELECT * FROM v_theses_full
 WHERE is_published = 1;