fix(db): strip inline -- comments before splitting schema statements

The schema loader stripped only full-line -- comments, then split the
file on ';'. A trailing comment containing a semicolon (e.g. the
mobile_auth_sessions.session_id column: `-- uuid; carried inside...`)
chopped the CREATE TABLE in half, so MariaDB got the fragment and failed
with `error ... near '' at line 3`, crash-looping the server on boot.

Strip -- comments on every line (full-line and trailing) before the ';'
split. Safe because the schema never places -- inside a string literal.

Verified by running ensureSchema() against a fresh MariaDB: all 49 tables
create cleanly and mobile_auth_sessions has all 11 columns.

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

server/src/utils/db.js

@@ -51,11 +51,16 @@ async function ensureSchema({ retries = 10, delayMs = 2000 } = {}) {
       const conn = await pool.getConnection()
       try {
         const sql = fs.readFileSync(SCHEMA_PATH, 'utf8')
-        // Strip full-line comments first, then split — so a leading comment block
-        // doesn't get glued onto (and discard) the statement that follows it.
+        // Strip `--` comments (full-line AND trailing) before splitting — so a
+        // leading comment block doesn't get glued onto the statement that follows
+        // it, and a `;` inside a trailing comment can't chop a statement in half.
+        // Safe because the schema never puts `--` inside a string literal.
         const statements = sql
           .split('\n')
-          .filter((line) => !line.trim().startsWith('--'))
+          .map((line) => {
+            const i = line.indexOf('--')
+            return i === -1 ? line : line.slice(0, i)
+          })
           .join('\n')
           .split(';')
           .map((s) => s.trim())