fix: use UTC-aware datetime for bucket.created default

[fanxing11]

`datetime.now()` without arguments returns a naive local datetime. When peewee stores it and `iso8601.parse_date` later serializes it, the parser tags the bare datetime as UTC by default — so `bucket.created` ends up shifted by the host's TZ offset.

Switching to `datetime.now(timezone.utc)` produces a proper UTC-aware datetime, matching the convention that watchers already use for event timestamps.

Applied the same fix to `EventModel.timestamp` for consistency, though that default is rarely hit since watchers provide their own timestamps.

Fixes #134

[greptile-apps]

Greptile Summary

This PR fixes a timezone bug where BucketModel.created (and EventModel.timestamp) defaulted to datetime.now(), a naive local datetime. Because iso8601.parse_date assumes UTC when there is no offset, timestamps from non-UTC hosts were silently shifted by the local TZ offset. Switching the defaults to lambda: datetime.now(timezone.utc) ensures the stored value is already in UTC, so round-tripping through SQLite and iso8601.parse_date produces the correct wall-clock time regardless of host timezone.

• BucketModel.created: now uses lambda: datetime.now(timezone.utc) so newly-created buckets always record an accurate UTC creation time.
• EventModel.timestamp: same fix applied for consistency, though this default is rarely exercised since watchers supply their own timestamps via EventModel.from_event.

Confidence Score: 5/5

Safe to merge — a two-line targeted fix that corrects an observable datetime offset bug with no side effects on the rest of the storage layer.

The change is minimal and self-contained: timezone is already imported, the lambda wrapper is the idiomatic peewee pattern for callable defaults, and the UTC time value is correct regardless of whether peewee strips the +00:00 suffix when writing to SQLite. No existing logic is restructured and no interfaces change.

No files require special attention.

Important Files Changed

Filename	Overview
aw_datastore/storages/peewee.py	Changes BucketModel.created and EventModel.timestamp defaults from datetime.now (naive local time) to lambda: datetime.now(timezone.utc) (UTC-aware); timezone is already imported on line 4 and the rest of the file is unchanged.

Sequence Diagram

sequenceDiagram
    participant Watcher
    participant PeeweeStorage
    participant BucketModel
    participant SQLite
    participant iso8601

    Watcher->>PeeweeStorage: "create_bucket(bucket_id, ..., created=...)"
    PeeweeStorage->>BucketModel: "BucketModel.create(created=created, ...)"
    Note over BucketModel: If created not provided, default fires
    Note over BucketModel: datetime.now(timezone.utc) → UTC-aware datetime
    BucketModel->>SQLite: store datetime string (UTC value)

    Watcher->>PeeweeStorage: get_metadata(bucket_id)
    PeeweeStorage->>BucketModel: BucketModel.get(...).json()
    BucketModel->>SQLite: SELECT created FROM bucketmodel
    SQLite-->>BucketModel: 2024-01-01 00:00:00 (UTC value)
    BucketModel->>iso8601: parse_date(created string)
    Note over iso8601: iso8601 defaults bare datetime to UTC
    Note over iso8601: Result correct because value was already UTC
    iso8601-->>BucketModel: datetime(2024,1,1,0,0,0,UTC)
    BucketModel-->>PeeweeStorage: created 2024-01-01T00:00:00+00:00
    PeeweeStorage-->>Watcher: bucket metadata

Loading

_{Reviews (1): Last reviewed commit: "fix: use UTC-aware datetime for bucket.c..." | Re-trigger Greptile}