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/docs.html

@@ -0,0 +1,44 @@
+{% extends "base.html" %}
+
+{% block title %}Docs - Hermes{% endblock %}
+
+{% block content %}
+<h2>📚 Documentation Center</h2>
+
+<div class="card">
+    <p class="text-muted">{{ docs|length }} documents across all docs directories</p>
+</div>
+
+<div class="card">
+    {% if docs %}
+    <table>
+        <thead>
+            <tr>
+                <th>Title</th>
+                <th>Path</th>
+                <th>Size</th>
+                <th>Modified</th>
+                <th>Snippet</th>
+            </tr>
+        </thead>
+        <tbody>
+            {% for d in docs %}
+            <tr>
+                <td><a href="/docs/{{ d.rel_path }}">{{ d.title }}</a></td>
+                <td class="text-small text-muted">{{ d.rel_path }}</td>
+                <td class="text-small">{{ d.size }} B</td>
+                <td class="text-small">{{ d.mtime|int|dt }}</td>
+                <td class="text-small text-muted">{{ d.snippet[:80] }}</td>
+            </tr>
+            {% endfor %}
+        </tbody>
+    </table>
+    {% else %}
+        <p class="text-muted">No documents found</p>
+    {% endif %}
+</div>
+
+<p class="mt-20">
+    <a href="/" class="btn">← Back to Dashboard</a>
+</p>
+{% endblock %}