Rename Liens étudiant·e, add link name + edit dialog

- Rename 'Accès étudiant·e' → 'Liens étudiant·e' in acces.php
- Add 'name' column to share_links (schema.sql + ALTER TABLE migration)
- ShareLink::create() now accepts optional  parameter
- Add ShareLink::update() method for name/password/expiration
- Add 'update' action to acces-etudiante.php controller
- Remove Visiter (play) button; row click opens link in new tab
- Add edit dialog with name, password, expiration fields
- Add pen icon button to open edit dialog per row
- Add Nom column to table (also in archived links section)

app/storage/schema.sql

@@ -338,6 +338,7 @@ INSERT OR IGNORE INTO pages (slug, title, content) VALUES
 CREATE TABLE IF NOT EXISTS share_links (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     slug TEXT NOT NULL UNIQUE,               -- Format: YYYYMMDD-<random>, e.g. 20260416-a3f9k2
+    name TEXT,                               -- user-defined label (optional)
     objet_restriction TEXT CHECK (objet_restriction IN ('tfe', 'thèse', 'frart')), -- NULL = no restriction
     password_hash TEXT,                      -- bcrypt hash; NULL = no password required
     is_active INTEGER NOT NULL DEFAULT 1,    -- 1 = active, 0 = disabled