fix(gui,cli,core): offer the CAPTCHA in the browser when the web view cannot start (B195)

The verification window now runs in its own process, so the app survives
when WebKit cannot start its sandbox on secureblue, but the CAPTCHA still
could not be solved there (#29). WebKit binds the journal socket with
`--ro-bind-try`, bubblewrap only skips a missing path, not an unreadable
one, and WebKit has no switch to leave the socket out.

Proton Mail Bridge never uses a web view: it opens verify.proton.me in the
system browser and retries with the original challenge token, typed with
the offered methods. Do the same as a fallback.

- core: `browser_verification_url` and `browser_verified` build the page
  URL and the retry credential from the challenge
- gui: when the verification window fails, a dialog opens the page in the
  browser and continues the sign-in once the user is done
- cli: `pdfs login` handles a CAPTCHA the same way instead of failing
- i18n: translate the new dialog in every catalog
- docs: B195, TROUBLESHOOTING.md, ARCHITECTURE.md, changelog

Fixes #29

po/fr.po

@@ -5,7 +5,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: proton-drive-linux 2.1.0\n"
 "Report-Msgid-Bugs-To: https://github.com/narrrl/proton-drive-linux/issues\n"
-"POT-Creation-Date: 2026-10-08 10:15+0200\n"
+"POT-Creation-Date: 2026-10-08 18:47+0200\n"
 "PO-Revision-Date: 2026-09-23 12:00+0200\n"
 "Last-Translator: Proton Drive for Linux contributors\n"
 "Language-Team: French\n"
@@ -275,8 +275,9 @@ msgstr ""
 #: crates/pdfs-gui/src/app/pages/locations.rs:1013
 #: crates/pdfs-gui/src/app/pages/locations.rs:1488
 #: crates/pdfs-gui/src/app/pages/locations.rs:1538
-#: crates/pdfs-gui/src/app/pages/login.rs:393
-#: crates/pdfs-gui/src/app/pages/login.rs:507
+#: crates/pdfs-gui/src/app/pages/login.rs:389
+#: crates/pdfs-gui/src/app/pages/login.rs:503
+#: crates/pdfs-gui/src/app/pages/login.rs:549
 #: crates/pdfs-gui/src/app/pages/photos.rs:2055
 #: crates/pdfs-gui/src/app/pages/shared.rs:946
 #: crates/pdfs-gui/src/app/pages/shared.rs:1027
@@ -3201,35 +3202,25 @@ msgstr "Saisissez votre adresse électronique et votre mot de passe."
 msgid "Signing in…"
 msgstr "Connexion…"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:164
+#: crates/pdfs-gui/src/app/pages/login.rs:160
 msgid "Complete the verification to continue…"
 msgstr "Terminez la vérification pour continuer…"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:197
+#: crates/pdfs-gui/src/app/pages/login.rs:195
 msgid "login cancelled"
 msgstr "connexion annulée"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:210
-msgid ""
-"The verification page couldn't be opened, so the sign-in was cancelled. Your "
-"system may keep the web view's sandbox from starting; the troubleshooting "
-"guide explains what to do."
-msgstr ""
-"La page de vérification n’a pas pu s’ouvrir, la connexion a donc été "
-"annulée. Votre système empêche peut-être le démarrage du bac à sable de la "
-"vue web ; le guide de dépannage explique la marche à suivre."
-
-#: crates/pdfs-gui/src/app/pages/login.rs:233
+#: crates/pdfs-gui/src/app/pages/login.rs:228
 msgid "Too many sign-in attempts. Wait a few minutes and try again."
 msgstr ""
 "Trop de tentatives de connexion. Patientez quelques minutes et réessayez."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:239
+#: crates/pdfs-gui/src/app/pages/login.rs:234
 msgid "Couldn't reach Proton. Check your internet connection and try again."
 msgstr ""
 "Impossible de joindre Proton. Vérifiez votre connexion Internet et réessayez."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:242
+#: crates/pdfs-gui/src/app/pages/login.rs:237
 msgid ""
 "Signed in, but the session couldn't be saved to the system keyring. Make "
 "sure a keyring (GNOME Keyring or KWallet) is running and unlocked."
@@ -3238,21 +3229,21 @@ msgstr ""
 "système. Assurez-vous qu’un trousseau (GNOME Keyring ou KWallet) est en "
 "cours d’exécution et déverrouillé."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:245
+#: crates/pdfs-gui/src/app/pages/login.rs:240
 msgid "Sign-in cancelled: no two-factor code was entered."
 msgstr "Connexion annulée : aucun code à deux facteurs n’a été saisi."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:248
+#: crates/pdfs-gui/src/app/pages/login.rs:243
 msgid "Sign-in cancelled: no mailbox password was entered."
 msgstr ""
 "Connexion annulée : aucun mot de passe de boîte aux lettres n’a été saisi."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:251
+#: crates/pdfs-gui/src/app/pages/login.rs:246
 msgid "That mailbox password didn't unlock your account."
 msgstr ""
 "Ce mot de passe de boîte aux lettres n’a pas déverrouillé votre compte."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:254
+#: crates/pdfs-gui/src/app/pages/login.rs:249
 msgid ""
 "Sign-in cancelled: the verification wasn't completed. Sign in again to get a "
 "new one."
@@ -3261,37 +3252,37 @@ msgstr ""
 "pour en obtenir une nouvelle."
 
 #. Translators: {error} is an error message, usually in English.
-#: crates/pdfs-gui/src/app/pages/login.rs:259
+#: crates/pdfs-gui/src/app/pages/login.rs:254
 #, rust-format
 msgid "Sign-in failed: {error}"
 msgstr "Échec de la connexion : {error}"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:369
+#: crates/pdfs-gui/src/app/pages/login.rs:365
 msgid "That mailbox password didn't unlock your account. Try again."
 msgstr ""
 "Ce mot de passe de boîte aux lettres n’a pas déverrouillé votre compte. "
 "Réessayez."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:371
+#: crates/pdfs-gui/src/app/pages/login.rs:367
 msgid ""
 "This account has a separate mailbox password. Enter it to unlock your files."
 msgstr ""
 "Ce compte a un mot de passe de boîte aux lettres distinct. Saisissez-le pour "
 "déverrouiller vos fichiers."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:374
+#: crates/pdfs-gui/src/app/pages/login.rs:370
 msgid "Mailbox Password"
 msgstr "Mot de passe de la boîte aux lettres"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:380
+#: crates/pdfs-gui/src/app/pages/login.rs:376
 msgid "Mailbox password"
 msgstr "Mot de passe de la boîte aux lettres"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:384
+#: crates/pdfs-gui/src/app/pages/login.rs:380
 msgid "Keep unlocked on this computer"
 msgstr "Garder déverrouillé sur cet ordinateur"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:386
+#: crates/pdfs-gui/src/app/pages/login.rs:382
 msgid ""
 "Stores the unlock in the system keyring, so Proton Drive opens without "
 "asking after every login. Otherwise you enter the password once per session."
@@ -3300,49 +3291,70 @@ msgstr ""
 "Proton Drive s’ouvre sans demande après chaque connexion. Sinon, vous "
 "saisissez le mot de passe une fois par session."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:394
-#: crates/pdfs-gui/src/app/pages/login.rs:447
+#: crates/pdfs-gui/src/app/pages/login.rs:390
+#: crates/pdfs-gui/src/app/pages/login.rs:443
 msgid "Unlock"
 msgstr "Déverrouiller"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:446
+#: crates/pdfs-gui/src/app/pages/login.rs:442
 msgid "Proton Drive is locked. Enter your mailbox password to unlock it."
 msgstr ""
 "Proton Drive est verrouillé. Saisissez votre mot de passe de boîte aux "
 "lettres pour le déverrouiller."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:475
+#: crates/pdfs-gui/src/app/pages/login.rs:471
 msgid "Unlocked."
 msgstr "Déverrouillé."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:480
+#: crates/pdfs-gui/src/app/pages/login.rs:476
 msgid "Couldn't unlock"
 msgstr "Impossible de déverrouiller"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:493
+#: crates/pdfs-gui/src/app/pages/login.rs:489
 msgid "Two-Factor Authentication"
 msgstr "Authentification à deux facteurs"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:495
+#: crates/pdfs-gui/src/app/pages/login.rs:491
 msgid ""
 "Enter the code from your authenticator app, or one of your recovery codes."
 msgstr ""
 "Saisissez le code de votre application d’authentification ou l’un de vos "
 "codes de récupération."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:501
+#: crates/pdfs-gui/src/app/pages/login.rs:497
 msgid "Authentication code"
 msgstr "Code d’authentification"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:508
+#: crates/pdfs-gui/src/app/pages/login.rs:504
 msgid "Confirm"
 msgstr "Confirmer"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:536
+#: crates/pdfs-gui/src/app/pages/login.rs:535
+#
+msgid "Verify in Your Browser"
+msgstr "Vérifier dans le navigateur"
+
+#: crates/pdfs-gui/src/app/pages/login.rs:537
+msgid ""
+"The verification page can't be shown in the app on this system. Open it in "
+"your browser, complete it there, then come back and choose Continue."
+msgstr "La page de vérification ne peut pas s’afficher dans l’application sur ce système. Ouvrez-la dans votre navigateur, terminez-la, puis revenez et choisissez « Continuer »."
+
+#: crates/pdfs-gui/src/app/pages/login.rs:543
+#
+msgid "Open Verification Page"
+msgstr "Ouvrir la page de vérification"
+
+#: crates/pdfs-gui/src/app/pages/login.rs:550
+#
+msgid "Continue"
+msgstr "Continuer"
+
+#: crates/pdfs-gui/src/app/pages/login.rs:589
 msgid "Sign Out?"
 msgstr "Se déconnecter ?"
 
-#: crates/pdfs-gui/src/app/pages/login.rs:538
+#: crates/pdfs-gui/src/app/pages/login.rs:591
 msgid ""
 "Proton Drive will disconnect and stop syncing until you sign in again. Files "
 "already on this computer stay where they are."
@@ -3351,7 +3363,7 @@ msgstr ""
 "vous vous reconnectiez. Les fichiers déjà présents sur cet ordinateur "
 "restent en place."
 
-#: crates/pdfs-gui/src/app/pages/login.rs:540
+#: crates/pdfs-gui/src/app/pages/login.rs:593
 msgid "Sign Out"
 msgstr "Se déconnecter"
 
@@ -6139,6 +6151,15 @@ msgstr "{count} a"
 msgid "cannot reach the Proton Drive daemon: {error}"
 msgstr "impossible de joindre le démon Proton Drive : {error}"
 
+#~ msgid ""
+#~ "The verification page couldn't be opened, so the sign-in was cancelled. "
+#~ "Your system may keep the web view's sandbox from starting; the "
+#~ "troubleshooting guide explains what to do."
+#~ msgstr ""
+#~ "La page de vérification n’a pas pu s’ouvrir, la connexion a donc été "
+#~ "annulée. Votre système empêche peut-être le démarrage du bac à sable de "
+#~ "la vue web ; le guide de dépannage explique la marche à suivre."
+
 #~ msgid "Jump to a month"
 #~ msgstr "Aller à un mois"