fix(docs): update README and command output to clarify date handling for empty databases

Author: leostar0412

discord_activity_tracker/README.md

@@ -41,7 +41,7 @@ Orchestrates exporter fetch → DB upsert + raw JSON → Markdown export to `DIS
 | `--skip-markdown-export` | Skip writing Markdown from the DB to `DISCORD_CONTEXT_REPO_PATH`. |
 | `--skip-remote-push` | Skip git commit/push after Markdown export (when auto-commit is enabled). |
 | `--skip-pinecone` / `--ignore-pinecone` | Skip Pinecone upsert for Discord messages (`--ignore-pinecone` is a deprecated alias). |
-| `--since`, `--from-date`, `--start-time` | Exporter lower bound (`--after`): `YYYY-MM-DD` or ISO-8601 UTC. If omitted, resumes from latest DB message for the guild (or full history if empty). |
+| `--since`, `--from-date`, `--start-time` | Exporter lower bound (`--after`): `YYYY-MM-DD` or ISO-8601 UTC. If omitted, resumes from latest DB message for the guild (or today UTC only if empty). |
 | `--until`, `--to-date`, `--end-time` | Exporter upper bound (`--before`); same formats. Omitted = through present. |
 | `--channels` | Comma-separated channel IDs (overrides `DISCORD_CHANNEL_IDS`). |
 | `--task` | **Deprecated.** `sync` \| `export` \| `all` — prefer `--skip-*` flags. |

discord_activity_tracker/management/commands/run_discord_activity_tracker.py

@@ -151,7 +151,7 @@ def _resolve_exporter_date_bounds(
             )
         else:
             logger.debug(
-                "exporter lower bound: none (--since omitted, empty DB for guild scope)",
+                "exporter lower bound: today UTC only (--since omitted, empty DB for guild scope)",
             )
 
     if until is not None:
@@ -527,7 +527,7 @@ def add_arguments(self, parser):
             dest="since",
             help="Exporter lower bound (--after): YYYY-MM-DD or ISO-8601 (UTC). "
             "If omitted, uses the latest message time already in the DB for this guild "
-            "(and channel allowlist), or full history when the DB has no rows.",
+            "(and channel allowlist), or today (UTC) only when the DB has no rows.",
         )
         parser.add_argument(
             "--until",
@@ -655,7 +655,7 @@ def _handle_core(
                     )
                 else:
                     collector.stdout.write(
-                        "  Lower bound (--after): none (full history; empty DB or no since)"
+                        "  Lower bound (--after): today (UTC) only (empty DB, no --since)"
                     )
                 if before_date:
                     collector.stdout.write(

discord_activity_tracker/tests/test_run_command_coverage.py

@@ -102,7 +102,7 @@ def test_handle_core_dry_run_skip_sync_only(monkeypatch, settings):
     ):
         collector.cmd._handle_core(collector.options, collector)
     out = collector.stdout.getvalue()
-    assert "full history" in out or "none" in out.lower()
+    assert "today" in out.lower()
 
 
 @pytest.mark.django_db