feat(shell): add Request Access button and Go to My Space fallback on access gate

When a logged-in user visits a private space they don't have access to,
the gate now shows a "Request Access" button (calls POST /api/spaces/:slug/access-requests)
and a "Go to {username}'s Space" secondary link. Handles already-pending (409) gracefully.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/shell.ts

@@ -884,17 +884,20 @@ export function renderShell(opts: ShellOptions): string {
         } else {
           var userSlug = '';
           try { if (session && session.claims && session.claims.username) userSlug = session.claims.username; } catch(e) {}
-          var homeHref = userSlug
+          var mySpaceHref = userSlug
-            ? 'https://' + userSlug + '.rspace.online/'
+            ? 'https://' + userSlug.toLowerCase() + '.rspace.online/'
             : 'https://rspace.online/';
-          var homeLabel = userSlug ? 'Return to ' + userSlug : 'Return to rSpace';
+          var mySpaceLabel = userSlug ? 'Go to ' + userSlug + '\\\'s Space' : 'Go to rSpace';
           gate.innerHTML =
             '<div class="access-gate__card">' +
               '<div class="access-gate__icon">&#x1F512;</div>' +
               '<h2 class="access-gate__title">Private Space</h2>' +
               '<p class="access-gate__desc">You don\\\'t have access to <strong>' + slug + '</strong>.</p>' +
-              '<p class="access-gate__hint">This space is private. Ask the owner to invite you as a member.</p>' +
+              '<p class="access-gate__hint">This space is private. You can request access from the owner.</p>' +
-              '<a href="' + homeHref + '" class="access-gate__btn">' + homeLabel + '</a>' +
+              '<div class="access-gate__actions">' +
+                '<button class="access-gate__btn" id="gate-request-access">Request Access</button>' +
+                '<a href="' + mySpaceHref + '" class="access-gate__btn access-gate__btn--secondary">' + mySpaceLabel + '</a>' +
+              '</div>' +
             '</div>';
         }
 
@@ -914,6 +917,44 @@ export function renderShell(opts: ShellOptions): string {
             }
           });
         }
+
+        // Request access button handler
+        var reqBtn = document.getElementById('gate-request-access');
+        if (reqBtn) reqBtn.addEventListener('click', function() {
+          reqBtn.disabled = true;
+          reqBtn.textContent = 'Requesting...';
+          fetch('/api/spaces/' + encodeURIComponent(slug) + '/access-requests', {
+            method: 'POST',
+            headers: {
+              'Authorization': 'Bearer ' + session.accessToken,
+              'Content-Type': 'application/json'
+            },
+            body: JSON.stringify({})
+          })
+          .then(function(r) { return r.json().then(function(d) { return { status: r.status, data: d }; }); })
+          .then(function(res) {
+            if (res.status === 201) {
+              reqBtn.textContent = 'Request Sent ✓';
+              reqBtn.style.opacity = '0.7';
+              var hint = gate.querySelector('.access-gate__hint');
+              if (hint) hint.textContent = 'Your request has been sent to the space owner. You\\\'ll be notified when it\\\'s approved.';
+            } else if (res.status === 409) {
+              reqBtn.textContent = 'Request Pending';
+              reqBtn.style.opacity = '0.7';
+              var hint = gate.querySelector('.access-gate__hint');
+              if (hint) hint.textContent = 'You already have a pending access request for this space.';
+            } else {
+              reqBtn.textContent = 'Request Access';
+              reqBtn.disabled = false;
+              alert(res.data.error || 'Failed to send request');
+            }
+          })
+          .catch(function() {
+            reqBtn.textContent = 'Request Access';
+            reqBtn.disabled = false;
+            alert('Network error — please try again');
+          });
+        });
       }
     })();
 
@@ -1755,6 +1796,13 @@ const ACCESS_GATE_CSS = `
   transition: opacity 0.15s, transform 0.15s;
 }
 .access-gate__btn:hover { opacity: 0.9; transform: translateY(-1px); }
+.access-gate__btn:disabled { opacity: 0.6; cursor: default; transform: none; }
+.access-gate__btn--secondary {
+  background: transparent; border: 1px solid var(--rs-border, rgba(255,255,255,0.15));
+  color: var(--rs-text-secondary, #94a3b8);
+}
+.access-gate__btn--secondary:hover { border-color: var(--rs-border-strong, rgba(255,255,255,0.3)); color: var(--rs-text-primary, #e0e0e0); }
+.access-gate__actions { display: flex; flex-direction: column; gap: 0.75rem; align-items: center; }
 `;
 
 const WELCOME_CSS = `