Release under the SolidCraft name: binaries, assets and installers (#383)

* Release under the SolidCraft name: binaries, assets and installers

The desktop binary is now `solidcraft` and the CLI `solidcraft-cli` (the two app packages
are renamed; their folders move with the rest of the rename later). Every release asset is
named solidcraft-<ver>-… / SolidCraft-<ver>-windows-x64.exe, and the installers show the
SolidCraft product name.

Kept so existing installs keep updating (docs/compatibility.md):
- `solvecraft-cli` alias binary in every package, forwarding to solidcraft-cli with a
  deprecation note on stderr (tests/legacy_alias.rs).
- Linux app ID ai.storyteller.solvecraft (Flatpak ID, desktop entry, Wayland app_id).
- MSI UpgradeCode, so the MSI upgrades in place.
- deb Replaces/Conflicts/Provides and rpm Obsoletes/Provides solvecraft.
- An old-named .zsync copy so earlier AppImages find updates; a legacy .flatpakrepo copy.
- .solvecraft file associations; SOLVECRAFT_* fallbacks in the packaging scripts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

* MSI: register the legacy .solvecraft extension without a duplicate open verb

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

apps/solvecraft-cli/tests/kill_mid_save.rs

@@ -12,7 +12,7 @@ fn round_of(path: &std::path::Path) -> Option<String> {
 
 #[test]
 fn killed_mid_save_the_old_file_survives() {
-    let exe = env!("CARGO_BIN_EXE_solvecraft-cli");
+    let exe = env!("CARGO_BIN_EXE_solidcraft-cli");
     let dir = std::env::temp_dir().join(format!("solvecraft-kill-mid-save-{}", std::process::id()));
     let _ = std::fs::remove_dir_all(&dir);
     std::fs::create_dir_all(&dir).unwrap();