feat: project overview + timeline + docs center

- services/task_project_linker.py: task<->project mapping (title keywords + workspace_path)
- routes/pages.py: /timeline, /docs, /docs/<path>, enhanced /projects/<name> and /tasks/<id>
- templates: timeline.html, docs.html, doc_view.html (new), project_detail.html + task_detail.html (overhauled)
- config.py: DOCS_DIRS + ProjectConfig color
- base.html: Timeline + Docs nav links

templates/task_detail.html

@@ -12,6 +12,12 @@
 {% set task = data.task %}
 <h2>📋 Task #{{ task.id }}: {{ task.title }}</h2>
 
+{% if project_name %}
+<div class="card mb-20">
+    <p><strong>📦 Project:</strong> <a href="/projects/{{ project_name }}">{{ project_name }}</a></p>
+</div>
+{% endif %}
+
 <div class="grid-2">
     <div>
         <div class="card">
@@ -44,6 +50,41 @@
             <pre>{{ task.result }}</pre>
         </div>
         {% endif %}
+
+        {% if commits %}
+        <div class="card">
+            <h3>🔀 Commits During Task ({{ commits|length }})</h3>
+            <table>
+                <thead>
+                    <tr><th>Hash</th><th>Time</th><th>Subject</th></tr>
+                </thead>
+                <tbody>
+                    {% for c in commits %}
+                    <tr>
+                        <td class="text-small"><a href="{{ c.gitea_url }}" target="_blank">{{ c.short }}</a></td>
+                        <td class="text-small">{{ c.ts|int|dt }}</td>
+                        <td>{{ c.subject }}</td>
+                    </tr>
+                    {% endfor %}
+                </tbody>
+            </table>
+        </div>
+        {% endif %}
+
+        {% if files_changed %}
+        <div class="card">
+            <h3>📁 Files Changed</h3>
+            {% for chash, files in files_changed.items() %}
+                <div class="text-small" style="margin-bottom:10px;">
+                    <strong>{{ chash }}</strong>:
+                    <ul style="margin-left:20px;">
+                        {% for f in files[:15] %}<li>{{ f }}</li>{% endfor %}
+                        {% if files|length > 15 %}<li class="text-muted">... {{ files|length - 15 }} more</li>{% endif %}
+                    </ul>
+                </div>
+            {% endfor %}
+        </div>
+        {% endif %}
     </div>
 
     <div>