Config: .env = projects root only; derive each project's forge from git

Reduce .env to just REPOS_HOST_PATH (the projects root); runtime bootstrap moves to compose/defaults. Projects are the subdirectories of the single root — removed the project-directories feature (store table, service methods, /api/config/project-dirs, Settings section). Each project's forge is derived from its git remote (matched to a configured forge, else the bare host) and shown as a pill next to its name (State.Forge via scanner ForgeFor + svc.ForgeDisplay). Removed first-run .env seeding; forges + identity are managed in Settings. Added forge.HostOf. AGENT.md updated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

components/repo-list/repo-list.js

@@ -116,6 +116,7 @@ class RepoList extends HTMLElement {
       });
       li.innerHTML = `
         <span class="name">${this.#esc(r.name)}</span>
+        ${r.forge ? `<span class="forge">${this.#esc(r.forge)}</span>` : ''}
         <span class="branch">${this.#esc(r.branch || '—')}</span>
         <span class="spacer"></span>
         ${r.ahead ? `<span class="badge ahead">↑${r.ahead}</span>` : ''}
@@ -166,6 +167,8 @@ class RepoList extends HTMLElement {
         li:hover { border-color: var(--border-strong); }
         li.selected { border-color: var(--fill-accent); background: var(--surface-2); }
         .name { font-weight: 600; }
+        .forge { font-size: 11px; color: var(--fill-accent); border: 1px solid var(--border-strong);
+                 border-radius: 999px; padding: 0 8px; }
         .branch { color: var(--color-fg-muted); }
         .spacer { margin-left: auto; }
         .badge {