Add firmware update notification nudge

[RCGV1]

Summary

Implements the connected-device stable firmware-update nudge from meshtastic/design#124:

• refreshes and evaluates the latest stable firmware release without blocking connection;
• presents a persistent, non-warning system_update_alt nudge with destination-specific copy and accessibility metadata;
• routes eligible Web devices to Meshtastic Flasher (the safe fallback because Web has no native OTA updater/capability registry);
• sends a browser notification only when permission is already granted, and only records dedupe after successful scheduling.

Closes #1303
Parent: meshtastic/design#124

Validation

• pnpm --filter meshtastic-web test — 36 files, 250 tests passed.
• Added targeted policy, presentation, reminder, browser-permission, and dedupe tests.
• pnpm --filter meshtastic-web check remains blocked by pre-existing formatting in src/pages/Connections/useConnections.ts; the full typecheck has existing cross-workspace failures unrelated to this change.

Manual verification

This is a draft pending browser UI evidence for a connected outdated device. It does not request browser-notification permission and has no hardware update execution path to verify.

[vercel]

Someone is attempting to deploy a commit to the Meshtastic Team on Vercel.

A member of the Team first needs to authorize it.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Benjamin Faershtein seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 52e07ff9-e4cf-487d-82e9-be57a574df12

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[RCGV1]

UI evidence

Browser-rendered connected-device firmware update state (local development fixture of the actual FirmwareUpdateNudge component). It shows the neutral system_update_alt affordance, stable/current version copy, and Meshtastic Flasher action.

This is visual evidence only; no physical-device update execution is claimed.