fix: validation error messages hidden by generic fallback in ErrorHandler::userMessage

ErrorHandler::userMessage only handled RuntimeException, but all validation
throws in ThesisCreateController and ThesisEditController use plain Exception.
This caused user-friendly messages like 'Le champ Nom/Prénom/Pseudo est requis'
to fall through to the 'Une erreur inattendue est survenue…' generic message.

Fix: add Exception check (after PDOException, since PDOException extends it)
so all validation exceptions pass their message through.

app/migrations/applied/034_dedup_all_lookup_tables.sql

@@ -0,0 +1,52 @@
+-- Migration 034: Deduplicate all lookup tables that have no UNIQUE on name/key/slug.
+-- Root cause: INSERT OR IGNORE is ineffective without a UNIQUE constraint,
+-- and schema.sql was applied repeatedly during broken-migration-runner era.
+
+-- ── access_types ──
+DELETE FROM access_types WHERE id NOT IN (SELECT MIN(id) FROM access_types GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_access_types_name_unique ON access_types(name);
+
+-- ── ap_programs ──
+DELETE FROM ap_programs WHERE id NOT IN (SELECT MIN(id) FROM ap_programs GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_ap_programs_name_unique ON ap_programs(name);
+
+-- ── finality_types ──
+DELETE FROM finality_types WHERE id NOT IN (SELECT MIN(id) FROM finality_types GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_finality_types_name_unique ON finality_types(name);
+
+-- ── languages ──
+DELETE FROM languages WHERE id NOT IN (SELECT MIN(id) FROM languages GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_languages_name_unique ON languages(name);
+
+-- ── license_types ──
+DELETE FROM license_types WHERE id NOT IN (SELECT MIN(id) FROM license_types GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_license_types_name_unique ON license_types(name);
+
+-- ── orientations ──
+DELETE FROM orientations WHERE id NOT IN (SELECT MIN(id) FROM orientations GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_orientations_name_unique ON orientations(name);
+
+-- ── pages ──
+DELETE FROM pages WHERE id NOT IN (SELECT MIN(id) FROM pages GROUP BY slug);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_pages_slug_unique ON pages(slug);
+
+-- ── apropos_contents ──
+DELETE FROM apropos_contents WHERE id NOT IN (SELECT MIN(id) FROM apropos_contents GROUP BY key);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_apropos_contents_key_unique ON apropos_contents(key);
+
+-- ── tags ──
+DELETE FROM tags WHERE id NOT IN (SELECT MIN(id) FROM tags GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_tags_name_unique ON tags(name);
+
+-- ── supervisors ──
+DELETE FROM supervisors WHERE id NOT IN (SELECT MIN(id) FROM supervisors GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_supervisors_name_unique ON supervisors(name);
+
+-- ── format_types ── (re-run in case any crept back)
+DELETE FROM format_types WHERE id NOT IN (SELECT MIN(id) FROM format_types GROUP BY name);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_format_types_name_unique ON format_types(name);
+
+-- ── Clean up authors with empty email (soft-deleted or dummy rows)
+-- These come from CSV import artefacts. Keep only the first per email.
+DELETE FROM authors WHERE id NOT IN (SELECT MIN(id) FROM authors GROUP BY email);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_authors_email_unique ON authors(email);