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

services/projects.py

@@ -6,6 +6,7 @@ import subprocess
 from typing import Any
 
 import config
+from services import task_project_linker
 
 logger = logging.getLogger(__name__)
 
@@ -159,3 +160,20 @@ def get_project_detail(name: str) -> dict[str, Any]:
     info["status_porcelain"] = status_porcelain
 
     return info
+
+
+def get_project_tasks(name: str) -> list[dict[str, Any]]:
+    """Tasks linked to a project (via task_project_linker)."""
+    return task_project_linker.link_project_tasks(name)
+
+
+def get_project_commits_in_window(
+    name: str,
+    start_ts: int | None = None,
+    end_ts: int | None = None,
+    limit: int = 20,
+) -> list[dict[str, Any]]:
+    """Commits for a project, optionally within a time window."""
+    return task_project_linker.link_project_commits(
+        name, limit=limit, since_ts=start_ts, until_ts=end_ts
+    )