fix: security audit — patch vulnerabilities V-02 through V-16

- V-02: XSS via innerHTML in profile.js — wrap err.message in escapeHtml()
- V-03: IDOR upload to other users' folders — add folder ownership check
- V-04: IDOR create folders in other users' trees — add parent ownership check
- V-06: Content-Disposition header injection — RFC 5987 percent-encoding
- V-08: WebDAV MOVE/COPY destination without ownership — add assert_owner checks
- V-09: .gitignore missing cert/key patterns — add *.pem, *.key, *.p12, etc.
- V-11: Username accepts XSS payloads — restrict to [a-zA-Z0-9._-]
- V-12: Minimal email validation — reject forbidden chars, require domain dot
- V-13: admin_reset_password doesn't invalidate sessions — revoke all sessions
- V-14: Rate limiting bypassable via X-Forwarded-For — gate behind OXICLOUD_TRUST_PROXY_HEADERS
- V-15: Cookie Secure flag off by default — default to true (safe-by-default)
- V-16: LIKE wildcard injection in searches — add like_escape() helper across 9 sites

src/infrastructure/repositories/pg/contact_pg_repository.rs

@@ -277,7 +277,7 @@ impl ContactRepository for ContactPgRepository {
     }
 
     async fn get_contacts_by_email(&self, email: &str) -> ContactRepositoryResult<Vec<Contact>> {
-        let search_pattern = format!("%{}%", email);
+        let search_pattern = super::like_escape(email);
 
         let rows = sqlx::query(
             r#"
@@ -339,7 +339,7 @@ impl ContactRepository for ContactPgRepository {
         address_book_id: &Uuid,
         query: &str,
     ) -> ContactRepositoryResult<Vec<Contact>> {
-        let search_pattern = format!("%{}%", query);
+        let search_pattern = super::like_escape(query);
 
         let rows = sqlx::query(
             r#"