Fix the icon filename that broke every desktop build

[RichardHightower]

The bug

cargo tauri build has never succeeded in this repo. This is why:

failed to bundle project: Failed to create app icon: `The image format could not be determined`

src-tauri/icons/henry.w@example.net is a 256×256 PNG — a scrubbing artifact from
128x128@2x.png. The Tauri bundler infers image format from the file extension, and
.net is not one.

Why it survived this long

CLAUDE.md documented it, and got it wrong:

Known latent bug: … an icon named icons/henry.w@example.net — a scrubbing
artifact from 128x128@2x.png. Harmless today (file and reference agree) but wrong.

The references did agree. tauri.conf.json pointed at a file that existed. Every check
you can perform by reading passed — which is exactly why it stayed on the "latent,
cosmetic" list across two releases instead of being fixed.

It was never harmless. It was a hard build failure standing between this repo and its
first binary, and the only way to discover that was to run the build.

Generalisable: "the references agree" is not "it works." The consistency was
checkable by reading; the format inference was not. CLAUDE.md now says so, with the
claim corrected in place rather than quietly deleted.

The fix

Rename the file and update the config together — the only way to change it without
breaking the reference:

src-tauri/icons/henry.w@example.net  ->  src-tauri/icons/128x128@2x.png

Verification — beyond "it compiled"

Check	Result
npm run build:desktop && npm run tauri:build	✅ succeeds
ForgeNotes.app	5.6 MB
ForgeNotes_0.3.0_aarch64.dmg	3.0 MB, arm64
Embedded icon	Contents/Resources/ForgeNotes.icns present
App launches and quits cleanly	✅
nm for mcp_bridge symbols in the release binary	0

That last row matters on its own. The MCP bridge is gated behind a cargo feature
specifically so release builds never contain it, and until now that was an untested
claim — there was no release build to test it against. It holds.

Still not done

• Unsigned and un-notarised. The .dmg will hit Gatekeeper on any machine but this
  one. Signing needs an Apple Developer identity and is a separate decision.
• arm64 only. No universal binary.
• Tauri warns the bundle identifier com.forgenotes.app ends in .app, which
  collides with the macOS bundle extension. Left alone deliberately: changing an
  identifier moves the app's data directory, so it is the user's call, not a drive-by.
• Binaries are not attached to a release here. The fix post-dates the v0.3.0 tag,
  so attaching this build to it would misrepresent what that tag contains.

Closes 01KZ3Z46SDWDGVD3CFZ0Z1S9FB.

🤖 Generated with Claude Code

https://claude.ai/code/session_012o4dVLL1GeMETrCbD8Hgc2