Add launcher engine (scopenet-core) and admin panel server

- scopenet-shared: wire types for branding, auth, instances, manifests
- scopenet-core: Mojang versions/libraries/assets, automatic Java runtimes,
  Fabric/Quilt/Forge/NeoForge installation, file sync, launch command
  builder, Microsoft auth, servers.dat injection, server list ping
- scopenet-panel: Axum + SQLite admin API with JWT auth, users/groups,
  branding, settings, instances, Modrinth/CurseForge/zip import, file
  hosting and launch stats

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011ARcGWxLx21FwXJ3yfGriS

panel/server/src/routes/meta.rs

@@ -0,0 +1,79 @@
+//! Version pickers and modpack search, proxied so the browser never needs
+//! API keys.
+
+use crate::auth::AdminUser;
+use crate::error::AppResult;
+use crate::packs;
+use crate::state::AppState;
+use axum::extract::{Path, Query, State};
+use axum::Json;
+use scopenet_core::meta::{self, LoaderVersion};
+use scopenet_shared::Loader;
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize)]
+pub struct McVersion {
+    id: String,
+    kind: String,
+    released: Option<String>,
+}
+
+pub async fn minecraft(_: AdminUser, State(state): State<AppState>) -> AppResult<Json<serde_json::Value>> {
+    let m = meta::mojang_manifest(&state.http).await?;
+    let versions: Vec<McVersion> = m
+        .versions
+        .into_iter()
+        .map(|v| McVersion { id: v.id, kind: v.kind, released: v.release_time })
+        .collect();
+    Ok(Json(serde_json::json!({ "latest": m.latest, "versions": versions })))
+}
+
+#[derive(Deserialize)]
+pub struct LoaderQuery {
+    mc: String,
+}
+
+pub async fn loaders(_: AdminUser, State(state): State<AppState>, Path(loader): Path<String>, Query(q): Query<LoaderQuery>) -> AppResult<Json<Vec<LoaderVersion>>> {
+    let loader = Loader::parse(&loader).unwrap_or_default();
+    Ok(Json(meta::loader_versions(&state.http, loader, &q.mc).await?))
+}
+
+#[derive(Deserialize)]
+pub struct SearchQuery {
+    #[serde(default)]
+    q: String,
+}
+
+pub async fn modrinth_search(_: AdminUser, State(state): State<AppState>, Query(q): Query<SearchQuery>) -> AppResult<Json<serde_json::Value>> {
+    let resp = state
+        .http
+        .get("https://api.modrinth.com/v2/search")
+        .query(&[("query", q.q.as_str()), ("facets", r#"[["project_type:modpack"]]"#), ("limit", "24"), ("index", "relevance")])
+        .send()
+        .await
+        .map_err(anyhow::Error::from)?
+        .error_for_status()
+        .map_err(anyhow::Error::from)?;
+    Ok(Json(resp.json().await.map_err(anyhow::Error::from)?))
+}
+
+pub async fn modrinth_versions(_: AdminUser, State(state): State<AppState>, Path(project): Path<String>) -> AppResult<Json<Vec<packs::MrVersion>>> {
+    let url = format!("https://api.modrinth.com/v2/project/{}/version", urlencode(&project));
+    Ok(Json(scopenet_core::http::get_json(&state.http, &url).await?))
+}
+
+pub async fn curseforge_search(_: AdminUser, State(state): State<AppState>, Query(q): Query<SearchQuery>) -> AppResult<Json<serde_json::Value>> {
+    let path = format!(
+        "/mods/search?gameId=432&classId=4471&pageSize=24&sortField=2&sortOrder=desc&searchFilter={}",
+        urlencode(&q.q)
+    );
+    Ok(Json(packs::cf_raw_get(&state, &path).await?))
+}
+
+pub async fn curseforge_files(_: AdminUser, State(state): State<AppState>, Path(mod_id): Path<i64>) -> AppResult<Json<serde_json::Value>> {
+    Ok(Json(packs::cf_raw_get(&state, &format!("/mods/{mod_id}/files?pageSize=40")).await?))
+}
+
+fn urlencode(s: &str) -> String {
+    percent_encoding::utf8_percent_encode(s, percent_encoding::NON_ALPHANUMERIC).to_string()
+}