Fix queued jobs incorrectly skipped after duplicate execution detection (#341)

When the same file was queued multiple times from the archive, all jobs
after the first were automatically skipped with "already printed X hours
ago". The scheduler's 4-hour safety check compared the shared archive's
completed_at timestamp, incorrectly treating legitimate repeat prints as
phantom reprints from crash recovery. This also affected single queue
items created from recently completed archives.

Remove the check entirely — the crash scenario it guarded against is
already prevented by committing item.status="printing" before sending
the print command.

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to Bambuddy will be documented in this file.
 - **File Downloads Show Generic Filenames** ([#334](https://github.com/maziggy/bambuddy/issues/334)) — Downloaded files with special characters in their names (spaces, umlauts, parentheses) were saved as generic `file_1`, `file_2` instead of the original filename. The `Content-Disposition` header parser now handles RFC 5987 percent-encoded filenames (`filename*=utf-8''...`) used by FastAPI for non-ASCII characters. Fix applied to all download endpoints (library files, archives, source files, F3D files, project exports, support bundles, printer files).
 - **Printer Card Cover Image Not Updating Between Prints** — The cover image on the printer card only refreshed on page reload. The `<img>` URL was always the same (`/printers/{id}/cover`) regardless of which print was active, so the browser served its cached image. Now appends the print name as a cache-busting query parameter so the browser fetches the new cover when a different print starts.
 - **Telegram Bold Title Broken by Underscores in Message** ([#332](https://github.com/maziggy/bambuddy/issues/332)) — Telegram notifications showed literal `*Title*` asterisks instead of bold text when the message body contained underscores (e.g. job name `A1_plate_8`, error code `0300_0001`). The code was disabling Markdown parsing entirely when underscores were detected. Now escapes underscores in the body with `\_` so Markdown rendering stays enabled.
+- **Queued Jobs Incorrectly Archived After Duplicate Execution Detection** ([#341](https://github.com/maziggy/bambuddy/issues/341)) — When the same file was added to the print queue multiple times, only the first job executed. All subsequent jobs were automatically skipped with "already printed X hours ago" because they shared the same archive reference, and a safety check incorrectly treated them as phantom reprints. The same issue also affected single queue items created from recently completed archives. Removed the overly broad 4-hour duplicate detection check — the crash recovery scenario it guarded against is already handled by the queue item status lifecycle.
 
 ### New Features
 - **External Links: Open in New Tab** ([#338](https://github.com/maziggy/bambuddy/issues/338)) — External sidebar links can now optionally open in a new browser tab instead of an iframe. Sites behind reverse proxies (Traefik, nginx) that send `X-Frame-Options: SAMEORIGIN` or CSP `frame-ancestors` headers block iframe embedding, causing "refused to connect" errors. A new "Open in new tab" toggle in the add/edit link modal lets users choose per-link. Keyboard shortcuts (number keys) also respect the setting. Defaults to iframe (existing behavior) for backward compatibility.

backend/app/services/print_scheduler.py

@@ -4,7 +4,7 @@ import asyncio
 import json
 import logging
 import zipfile
-from datetime import datetime, timedelta
+from datetime import datetime
 from pathlib import Path
 
 import defusedxml.ElementTree as ET
@@ -862,27 +862,6 @@ class PrintScheduler:
                 await self._power_off_if_needed(db, item)
                 return
 
-            # Safety: Check if this archive was printed recently (within 4 hours)
-            # This prevents phantom reprints if a queue item got stuck in "pending"
-            # after its print already started due to a crash/restart
-            if archive.status == "completed" and archive.completed_at:
-                completed_at = (
-                    archive.completed_at.replace(tzinfo=None) if archive.completed_at.tzinfo else archive.completed_at
-                )
-                time_since_completed = datetime.utcnow() - completed_at
-                if time_since_completed < timedelta(hours=4):
-                    logger.warning(
-                        f"Queue item {item.id}: Archive {item.archive_id} was already printed "
-                        f"{time_since_completed.total_seconds() / 3600:.1f} hours ago, skipping to prevent duplicate"
-                    )
-                    item.status = "skipped"
-                    item.error_message = (
-                        f"Archive was already printed {time_since_completed.total_seconds() / 3600:.1f} hours ago"
-                    )
-                    item.completed_at = datetime.utcnow()
-                    await db.commit()
-                    return
-
             file_path = settings.base_dir / archive.file_path
             filename = archive.filename