fix(diagnostics): deep-review round 1 — a send that cannot race, lose or repeat itself

The send, the draft and the screenshots take the session's row lock, so an
autosave or a paste during a send waits for it and then sees it, and two sends
cannot open two issues. A save keeps the delivery's progress; a failed edit
that shows the screenshots is finished by the retry; an answer that is not the
tracker's API (a redirect, a proxy page) is refused, not a crash that loses the
issue's record. Only an attempt that opened an issue counts toward the pace.

Screenshots: deleting one after the send is refused, a user's storage is
capped across sessions, new sessions and zip exports are paced, images are
stored uncompressed in the zip. One liveness rule, one session view, one image
type table.

Logging: a session's elevation is tracked apart from the user's own, so the
browser's own requests (no header) no longer lower the floor a session needs;
Stop ends it at once.

Composer: an image pasted anywhere is taken; what is still unsaved is saved on
close, and "saved" is shown only when it is; the draft is held while it is
sent; a failed screenshot read says so instead of reading as none; focus moves
to what stays; the preview follows the text size. Pill: the step prompt and a
running Stop survive the pill moving between hosts, the prompt keeps the
dialog's Tab trap, the toast region lets clicks through, other tabs hear of a
Start or Stop, the last seconds are sent before the cap, a capture with no
frame is an error.

frontend/src/i18n/locales/en/errors.json

@@ -222,6 +222,9 @@
     "issues_public_repo": "The issue repository is public. Because of the log, reports go only to a private one.",
     "issues_disabled": "The issue repository has its issue tracker switched off.",
     "issues_rejected": "The issue tracker refused the request.",
-    "issues_rate_limited": "You can send at most 5 reports an hour. Try again later."
+    "issues_rate_limited": "You can send at most {{limit}} reports an hour. Try again later.",
+    "debug_session_rate_limited": "You can start at most {{limit}} new recordings an hour. Try again later.",
+    "export_rate_limited": "Too many downloads in a row. Wait a minute.",
+    "screenshot_storage_full": "You've reached the {{limit}} MB screenshot allowance. Remove images from older sessions, or wait until they expire."
   }
 }

frontend/src/i18n/locales/en/recorder.json

@@ -105,7 +105,9 @@
     "preview": "Preview",
     "previewFailed": "Couldn't load the preview",
     "previewTitle": "Preview of the report",
-    "previewLocal": "Without an issue tracker, this is the zip's issue.md."
+    "previewLocal": "Without an issue tracker, this is the zip's issue.md.",
+    "shotsFailed": "Couldn't load the screenshots",
+    "removeShotFailed": "Couldn't remove the screenshot"
   },
   "issue": {
     "steps": "Steps",

frontend/src/i18n/locales/hu/errors.json

@@ -222,6 +222,9 @@
     "issues_public_repo": "A hibajegy-tárhely nyilvános. A napló miatt csak privát tárhelyre küldünk.",
     "issues_disabled": "A hibajegy-tárhelyen ki van kapcsolva a hibajegy-kezelés.",
     "issues_rejected": "A hibajegy-kezelő visszautasította a kérést.",
-    "issues_rate_limited": "Óránként legfeljebb 5 hibajegyet küldhetsz. Próbáld újra később."
+    "issues_rate_limited": "Óránként legfeljebb {{limit}} hibajegyet küldhetsz. Próbáld újra később.",
+    "debug_session_rate_limited": "Óránként legfeljebb {{limit}} új rögzítést indíthatsz. Próbáld újra később.",
+    "export_rate_limited": "Túl sok letöltés egymás után. Várj egy percet.",
+    "screenshot_storage_full": "Elérted a képernyőképek {{limit}} MB-os keretét. Törölj régebbi munkamenetekből képeket, vagy várd meg, amíg lejárnak."
   }
 }

frontend/src/i18n/locales/hu/recorder.json

@@ -105,7 +105,9 @@
     "preview": "Előnézet",
     "previewFailed": "Nem sikerült betölteni az előnézetet",
     "previewTitle": "A hibajegy előnézete",
-    "previewLocal": "Hibajegy-kezelő nélkül ez a zip issue.md fájlja."
+    "previewLocal": "Hibajegy-kezelő nélkül ez a zip issue.md fájlja.",
+    "shotsFailed": "Nem sikerült betölteni a képernyőképeket",
+    "removeShotFailed": "Nem sikerült törölni a képernyőképet"
   },
   "issue": {
     "steps": "Lépések",