GitHub workflows (#428)

Fixes #348 
Fixes #274 
Fixes #149 

- Connect to existing repos
- Push to other branches on GitHub besides main
- Allows force push (with confirmation) dialog

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Co-authored-by: graphite-app[bot] <96075541+graphite-app[bot]@users.noreply.github.com>

src/db/schema.ts

@@ -14,6 +14,7 @@ export const apps = sqliteTable("apps", {
     .default(sql`(unixepoch())`),
   githubOrg: text("github_org"),
   githubRepo: text("github_repo"),
+  githubBranch: text("github_branch"),
   supabaseProjectId: text("supabase_project_id"),
   chatContext: text("chat_context", { mode: "json" }),
 });