feat: add backend pagination support for infinite scroll in issues and pulls

Update ListAllIssues and ListAllPullRequests to accept state and page
parameters, returning paginated results (20 per page) with HasMore
metadata. ListIssues and ListPulls handlers now read page, org, and
state query params; HTMX requests for page > 1 return only card HTML
fragments for seamless infinite scroll. Both templates extract a
reusable "cards" block and pulls.html gains a scroll sentinel matching
the existing issues.html pattern. Filter changes reset to page 1.

Closes leeworks-agents/gitea-mobile#32

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/templates/issues.html

@@ -1,3 +1,25 @@
+{{define "cards"}}
+  {{range .Issues}}
+  <div class="card" hx-get="/issues/{{.RepoOwner}}/{{.RepoName}}/{{.Number}}" hx-target="#main-content" hx-swap="innerHTML" hx-push-url="true">
+    <div class="card-title">{{.Title}}</div>
+    <div class="card-meta">
+      <span>{{.RepoOwner}}/{{.RepoName}} #{{.Number}}</span>
+      {{range .Labels}}
+      <span class="label" style="color:#{{.Color}};border:1px solid #{{.Color}}">{{.Name}}</span>
+      {{end}}
+      {{if .Assignee}}
+      <span>{{.Assignee.Login}}</span>
+      {{end}}
+    </div>
+  </div>
+  {{end}}
+  {{if .HasMore}}
+  <div class="scroll-sentinel" hx-get="/issues?page={{.NextPage}}&org={{.SelectedOrg}}&state={{.SelectedState}}" hx-trigger="revealed" hx-swap="outerHTML" hx-target="this">
+    <div class="spinner htmx-indicator"></div>
+  </div>
+  {{end}}
+{{end}}
+
 {{define "content"}}
 <h1>Issues</h1>
 
@@ -20,25 +42,7 @@
 <p class="empty">No issues found.</p>
 {{else}}
 <div id="issue-list">
-  {{range .Issues}}
-  <div class="card" hx-get="/issues/{{.RepoOwner}}/{{.RepoName}}/{{.Number}}" hx-target="#main-content" hx-swap="innerHTML" hx-push-url="true">
-    <div class="card-title">{{.Title}}</div>
-    <div class="card-meta">
-      <span>{{.RepoOwner}}/{{.RepoName}} #{{.Number}}</span>
-      {{range .Labels}}
-      <span class="label" style="color:#{{.Color}};border:1px solid #{{.Color}}">{{.Name}}</span>
-      {{end}}
-      {{if .Assignee}}
-      <span>{{.Assignee.Login}}</span>
-      {{end}}
-    </div>
-  </div>
-  {{end}}
-  {{if .HasMore}}
-  <div class="scroll-sentinel" hx-get="/issues?page={{.NextPage}}&org={{.SelectedOrg}}&state={{.SelectedState}}" hx-trigger="revealed" hx-swap="outerHTML" hx-target="this">
-    <div class="spinner htmx-indicator"></div>
-  </div>
-  {{end}}
+  {{template "cards" .}}
 </div>
 {{end}}
 {{end}}

internal/templates/pulls.html

@@ -1,3 +1,28 @@
+{{define "cards"}}
+  {{range .Pulls}}
+  <div class="card" hx-get="/pulls/{{.RepoOwner}}/{{.RepoName}}/{{.Number}}" hx-target="#main-content" hx-swap="innerHTML" hx-push-url="true">
+    <div class="card-title">
+      <span class="type-badge type-pull">PR</span>
+      {{.Title}}
+    </div>
+    <div class="card-meta">
+      <span>{{.RepoOwner}}/{{.RepoName}} #{{.Number}}</span>
+      {{range .Labels}}
+      <span class="label" style="color:#{{.Color}};border:1px solid #{{.Color}}">{{.Name}}</span>
+      {{end}}
+      <span class="diff-add">+{{.Additions}}</span>
+      <span class="diff-del">-{{.Deletions}}</span>
+      {{if .Mergeable}}<span style="color:var(--accent-green);font-size:0.7rem;">mergeable</span>{{end}}
+    </div>
+  </div>
+  {{end}}
+  {{if .HasMore}}
+  <div class="scroll-sentinel" hx-get="/pulls?page={{.NextPage}}&org={{.SelectedOrg}}" hx-trigger="revealed" hx-swap="outerHTML" hx-target="this">
+    <div class="spinner htmx-indicator"></div>
+  </div>
+  {{end}}
+{{end}}
+
 {{define "content"}}
 <h1>Pull Requests</h1>
 
@@ -16,23 +41,7 @@
 <p class="empty">No open pull requests found.</p>
 {{else}}
 <div id="pull-list">
-  {{range .Pulls}}
-  <div class="card" hx-get="/pulls/{{.RepoOwner}}/{{.RepoName}}/{{.Number}}" hx-target="#main-content" hx-swap="innerHTML" hx-push-url="true">
-    <div class="card-title">
-      <span class="type-badge type-pull">PR</span>
-      {{.Title}}
-    </div>
-    <div class="card-meta">
-      <span>{{.RepoOwner}}/{{.RepoName}} #{{.Number}}</span>
-      {{range .Labels}}
-      <span class="label" style="color:#{{.Color}};border:1px solid #{{.Color}}">{{.Name}}</span>
-      {{end}}
-      <span class="diff-add">+{{.Additions}}</span>
-      <span class="diff-del">-{{.Deletions}}</span>
-      {{if .Mergeable}}<span style="color:var(--accent-green);font-size:0.7rem;">mergeable</span>{{end}}
-    </div>
-  </div>
-  {{end}}
+  {{template "cards" .}}
 </div>
 {{end}}
 {{end}}