PROSERVE v1.5.3 migrations : idempotent SQLs (FK syntax fix)

Schema source-of-truth for the proserveapi DB, versioned outside the
release ZIPs (the actual binaries live in version/ but are gitignored).

0001_Init.sql — full bootstrap of proserveapi (12 tables + view +
reference data + FKs). Reworked from a phpMyAdmin dump to be safely
re-runnable on:
  - fresh install (everything created)
  - existing customer DB pre-populated manually before launcher rollout
  - re-import via phpMyAdmin or mysql CLI
Idempotency tools used:
  - CREATE TABLE IF NOT EXISTS
  - INSERT IGNORE INTO ...  for reference rows
  - ADD PRIMARY KEY / KEY / UNIQUE KEY IF NOT EXISTS
  - ADD FOREIGN KEY IF NOT EXISTS `name` (...)  REFERENCES ...
    (note: MariaDB does NOT accept `ADD CONSTRAINT IF NOT EXISTS name
     FOREIGN KEY ...` — the IF NOT EXISTS goes after FOREIGN KEY, not
     after CONSTRAINT)
  - CREATE OR REPLACE VIEW
  - Removed the dump's `START TRANSACTION` / `COMMIT` (the launcher
    wraps each script in its own tx; embedded BEGIN/COMMIT would break
    the rollback semantics)
  - Removed `DEFINER=root@localhost` (uses CURRENT_USER, more portable)

0002_SessionType_ps_1.4.5.sql — adds id=7 'LongRange' + renames id=6
to 'Rescue'. Now uses INSERT IGNORE for the new row (skips if 0001
already inserted it on a fresh install) and the UPDATE is naturally
idempotent.

0003_UserSize_ps_1.5.0.sql — adds users.size column. Now uses
ADD COLUMN IF NOT EXISTS (the column is also in the recent 0001
baseline, so on a fresh install this will skip; on an upgrade from a
pre-0003 DB it actually adds it).

Validated locally on MariaDB 10.4 (XAMPP) with two consecutive runs of
each file: exit code 0 on every run, no errors.

.gitignore tightened so version/ only tracks _migrations/*.sql — the
~14 GB UE5 binaries and the _report/ build artifacts stay out of git.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -28,6 +28,17 @@ packages/
 # Large game build (sample only — should not be in repo)
 ASTERION_VR/
 
+# Sources des releases PROSERVE en attente de zip/upload :
+# on ignore tout sauf les _migrations/ (SQL source-of-truth de la DB).
+# Le _report/ est un build artifact (Vue/React minifié) maintenu ailleurs.
+# Les binaires UE5 sont gigaoctets, à pousser uniquement via SFTP.
+version/*
+!version/.gitkeep
+!version/*/
+version/*/*
+!version/*/_migrations/
+version/*/_migrations/.htaccess
+
 # Server-side secrets — never commit (config.example.php sert de template)
 server/api/config.php
 # Le contenu de server/builds/ est ignoré (gros ZIPs / launcher.exe), mais on