Consolidate logos for the project.

[HuggeK]

Looks like there is: https://github.com/frahlg/forty-two-watts/blob/master/web/logo.jpg and also the https://raw.githubusercontent.com/frahlg/forty-two-watts/master/web/favicon.svg

Which one should we be using? Make a square one and a .svg if we would use the png one.

[HuggeK]

The logo has changed to FTW. @frahlg could you feed what your agent produced the png so we have a .svg logo too?(for the website and the rpi imager for example) so that we have one logo for all.

[frahlg]

Implemented locally on codex/logo-assets-discussion-529:

• added web/logo.svg as the canonical, deterministic vector logo;
• added a square 1024×1024 web/logo.png for Raspberry Pi Imager;
• regenerated the matching JPEG fallback and made the favicon a small-size version of the same FTW mark;
• switched the dashboard, setup wizard, and README to SVG, while Imager now points at the square PNG;
• added a changeset and a CI assertion for the Imager icon URL.

The palette and circuit-board character from the current FTW artwork are preserved, but the logo is now built from native vector paths so it scales cleanly. npm test and the full make verify both pass.

The branch is local and ready to publish as a draft PR; no remote branch or PR has been created yet.

[frahlg]

Follow-up: this is now published and merged in PR #601 (630cc69e).

Canonical assets on master:

• SVG logo
• square 1024×1024 PNG
• small favicon SVG

The dashboard, setup wizard, and README use the SVG; Raspberry Pi Imager uses the square PNG. All required GitHub checks passed before merge.