fix(logs): correct timestamp conversion causing 400 Bad Request

[platinummonkey]

Summary

Fixes a critical bug in the pup logs search command that was causing 400 Bad Request errors. The issue was incorrect timestamp conversion from milliseconds to seconds, resulting in dates in the year 57063 instead of 2026.

Also removes an obsolete unstable operation warning for v2.QueryTimeseriesData.

Changes

Timestamp Conversion Fix (cmd/logs_simple.go:658-659)

• Changed time.Unix(fromTime, 0) to time.UnixMilli(fromTime)
• Changed time.Unix(toTime, 0) to time.UnixMilli(toTime)
• The parseTimeString() function returns milliseconds, but time.Unix() expects seconds

Warning Fix (pkg/client/client.go:82)

• Removed v2.QueryTimeseriesData from unstable operations list
• This operation is no longer unstable in the API client library

Testing (cmd/logs_simple_test.go)

• Added TestParseTimeString to validate timestamp parsing
• Ensures timestamps are returned in milliseconds (13 digits)
• Tests relative times (1h, 7d) and "now"

Root Cause

When users ran:

pup logs search --query="service:storage-manager" --from="7d" --limit=20

The function would:

1. Parse "7d" to 1738971894000 milliseconds
2. Pass to time.Unix(1738971894000, 0) treating it as seconds
3. Create timestamp for year 57063
4. API rejects with 400 Bad Request

Testing

• ✅ All unit tests pass
• ✅ Race detector clean
• ✅ Build successful
• ✅ New test validates timestamp format

Related Issues

Fixes user-reported bug: Error: failed to search logs: 400 Bad Request (status: 400)

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🤖 Generated with Claude Code

[github-actions]

📊 Test Coverage Report

Overall Coverage: 75.5%

Threshold: 80% ❌

Coverage by Package

## Coverage by Package

- github.com/DataDog/pup/pkg/auth/callback/server.go:40: 81.2%
- github.com/DataDog/pup/pkg/auth/dcr/client.go:28: 100.0%
- github.com/DataDog/pup/pkg/auth/dcr/types.go:24: 100.0%
- github.com/DataDog/pup/pkg/auth/oauth/client.go:22: 100.0%
- github.com/DataDog/pup/pkg/auth/oauth/pkce.go:24: 85.7%
- github.com/DataDog/pup/pkg/auth/storage/factory.go:53: 94.7%
- github.com/DataDog/pup/pkg/auth/storage/keychain.go:44: 42.9%
- github.com/DataDog/pup/pkg/auth/storage/storage.go:58: 71.4%
- github.com/DataDog/pup/pkg/auth/types/types.go:23: 100.0%
- github.com/DataDog/pup/pkg/client/client.go:33: 94.4%
- github.com/DataDog/pup/pkg/config/config.go:22: 100.0%
- github.com/DataDog/pup/pkg/formatter/formatter.go:31: 100.0%
- github.com/DataDog/pup/pkg/util/time.go:20: 95.8%

## Summary

total:								(statements)		75.5%

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📈 Coverage Status: ❌ FAILED - Coverage below minimum threshold

_{Updated for commit 64446c1}