feat(nadia): Add database index and devlog query helper

Outcome: done
Changed: devplacepy/database/schema.py:45, devplacepy/database/engagement.py:3-5,194-210, devplacepy/database/__init__.py:11,118
Verified by: `python3 -m py_compile` on all three files — passed; `pyflakes` on engagement.py — clean (no warnings)
Findings: Index idx_posts_project_uid added to init_db at devplacepy/database/schema.py:45 (CREATE INDEX IF NOT EXISTS on posts.project_uid)
Findings: get_project_devlog(project_uid: str, before: str | None = None, viewer: dict | None = None) -> tuple[list, str | None] defined at devplacepy/database/engagement.py:194, returns (list of enriched post dicts, next_cursor) using paginate() with project_uid filter, auto-filtered for deleted_at IS NULL, batch helpers get_users_by_uids and get_comment_counts_by_post_uids, and enrich_items() for post enrichment including author, time_ago, my_vote, comment_count
Findings: get_project_devlog exported from devplacepy/database/__init__.py via import (line 11) and __all__ (line 118)
Open: None
Confidence: high - all acceptance criteria met, syntax verified, no warnings introduced

Typosaurus-Run: 45c0aee6df2649ffaa248729bdfd5841
Typosaurus-Node: 17f01a1e325e40ecb73ffe423f78c4a9
Typosaurus-Agent: @nadia
Refs: #135

devplacepy/database/engagement.py

@@ -1,6 +1,9 @@
 # retoor <retoor@molodetz.nl>
 
-from .core import TTLCache, _in_clause, db, defaultdict
+from .core import TTLCache, _in_clause, db, defaultdict, get_table
+from .pagination import paginate
+from devplacepy.content import enrich_items
+from .users import get_users_by_uids
 
 
 _comment_count_cache = TTLCache(ttl=15, max_size=10000)
@@ -185,3 +188,25 @@ def get_polls_by_post_uids(post_uids, user=None):
 
 def get_poll_for_post(post_uid, user=None):
     return get_polls_by_post_uids([post_uid], user).get(post_uid)
+
+
+def get_project_devlog(project_uid: str, before: str | None = None, viewer: dict | None = None) -> tuple[list, str | None]:
+    posts_table = get_table("posts")
+    posts, next_cursor = paginate(
+        posts_table,
+        before=before,
+        viewer_uid=viewer["uid"] if viewer else None,
+        project_uid=project_uid,
+    )
+    if not posts:
+        return [], None
+
+    authors = get_users_by_uids([p["user_uid"] for p in posts])
+    counts = get_comment_counts_by_post_uids([p["uid"] for p in posts])
+
+    result = enrich_items(
+        posts, "post", authors, {"comment_count": counts}, user=viewer
+    )
+    return result, next_cursor
+
+