Add granular failure reason tracking to Eqsl_mappings_model via last_failure_reason and last_db_error properties. Controller now differentiates between encryption failures, schema migration errors (DB error 1406), and generic DB errors, providing more actionable user-facing messages and structured error logging.
Adds migration 275 to convert eQSL password columns to TEXT and encrypt existing user/mapping passwords with an `enc:` prefix. Updates eQSL controller/model flows to decrypt on read, encrypt on create/update, and keep plaintext backward compatibility for legacy rows. User profile updates now avoid reusing stored ciphertext when no new password is submitted, and mapping updates report a clear error if secure password storage fails.
When editing or creating an eQSL mapping, the password field can now be left blank. Cloudlog will reuse an existing saved password for the same eQSL username. A password is only required when no saved password exists for that username. The mappings form hint text and docs are updated accordingly.
