Scheduled Downloads

[skapoor68]

This adds the ability for users to schedule recurring downloads of their Canvas courses. This is helpful for students who want their course materials automatically kept up to date locally, and for protecting against unplanned Canvas outages.

AI summary attached:

What's new

A Scheduled Downloads section in Settings lets users:

• Enable a recurring download on a fixed interval (12 h, 24 h, 48 h, or 7 days)
• Select which courses to include from a live list of their active Canvas enrollments
• See the last run timestamp and next scheduled run time

A small nudge link in the popup ("or schedule a recurring download") links directly to Settings for discoverability.

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Expected behavior

• When Canvas is open: the alarm fires and the download starts immediately in the active Canvas tab.
• When Canvas is closed or CPU is asleep: the pending run is saved to local storage. The next time the user opens any Canvas page, the run executes automatically before they interact with anything.
• Alarm durability: chrome.alarms survive browser restarts — if Chrome was closed when an alarm fired, it fires shortly after relaunch.
• Two tabs open simultaneously: the pending run is cleared before execution begins, so only one tab picks it up.
• All existing settings apply as-are (conflictAction, zipMode, contentTypes, folderPrefix, incrementalMode, throttle). No overrides.
• Disabling the toggle immediately unregisters the alarm and clears the config without requiring a Save. Enabling requires Save to register the alarm.
• Unenrolled/inaccessible courses are skipped gracefully (existing 401/403 handling in downloadCourse) and counted as failed without aborting the run.

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New storage keys

Key	Store	Purpose
scheduleConfig	sync	Enabled state, interval, selected course IDs and names — roams with Chrome profile
canvasDomain	local	Written once on first Canvas page load so the background service worker can locate an open Canvas tab
pendingRun	local	Deferred run waiting to execute; cleared immediately on pickup
lastScheduledRun	local	Timestamp and result of the most recent run; displayed in Settings

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New permissions

• alarms — fires the recurring schedule
• tabs — lets the background service worker find an open Canvas tab to deliver the download to; required for non-instructure.com Canvas domains where host permissions don't cover tab URL access

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Files changed

File	Change
manifest.json	Added alarms, tabs permissions
background.js	Alarm registration/unregistration, handleScheduleAlarm, findOpenCanvasTab, new message handlers
content.js	persistCanvasDomain, checkPendingDownload, runScheduledDownload, TRIGGER_SCHEDULED_DOWNLOAD message handler
options.js	Schedule UI: loadScheduleConfig, saveScheduleConfig, renderCoursePickerForSchedule, onScheduleToggle
options.html	Scheduled Downloads card with toggle, interval select, course picker, status lines
popup.html / popup.js	"Schedule a recurring download" nudge link
README.md / PRIVACY.md	Documented new feature and permissions