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>

xtask/src/book.rs

@@ -20,8 +20,8 @@ const SNAPSHOT_SIZE: (&str, &str) = ("960", "600");
 pub fn run(root: &Path, build: bool) -> Result<(), String> {
     let book = root.join("docs/book");
     let mut c = cargo();
-    c.args(["build", "-q", "--release", "-p", "solvecraft-cli"]);
-    crate::run(c, "cargo build -p solvecraft-cli")?;
+    c.args(["build", "-q", "--release", "-p", "solidcraft-cli"]);
+    crate::run(c, "cargo build -p solidcraft-cli")?;
 
     let out = cli().arg("commands").output().map_err(|e| format!("solvecraft-cli: {e}"))?;
     if !out.status.success() {
@@ -61,7 +61,7 @@ pub fn run(root: &Path, build: bool) -> Result<(), String> {
 /// The release solvecraft-cli just built.
 fn cli() -> std::process::Command {
     let mut c = cargo();
-    c.args(["run", "-q", "--release", "-p", "solvecraft-cli", "--"]);
+    c.args(["run", "-q", "--release", "-p", "solidcraft-cli", "--"]);
     c
 }