Add tests for log parsing and graph generation

[OlufemiAdeOlusile]

Summary

Added unit tests for the log-parsing and graph-generation code, previously the most logic-dense modules in the repo with zero coverage.

• log_analyzer.py: string search, rollback detection, and the combined check_db_sync_logs() warnings
• logs/metrics_extractor.py: node log parsing for both the JSON (CentiCpu) and human-readable (Cpu Ticks) tracer formats, CPU delta calculation, and tip/CPU carry-forward between samples
• db_sync/metrics_extractor.py: duration string parsing and a full epoch cycle (start, block inserts, stats, completion)
• sync_static_graphs.py: detect_json_mode() and normalize_dbsync_data() branch coverage, plus an end-to-end smoke test confirming generate_static_graphs() produces real PNG files from sample data

Found and documented one existing quirk while writing these: are_rollbacks_present_in_logs() only returns True once "rolling" appears a second time in the log, so a single rollback event is not reported. Left as-is and covered by a test describing the current behavior since this may be intentional, worth confirming with the team rather than changing silently.

Test plan

• All 28 new tests pass
• ruff and mypy pass across the whole sync_tests/ package (47 source files)
• Full local test suite (62 tests) collects and passes with no regressions

[Copilot]

Pull request overview

This PR adds unit and smoke tests covering previously untested, logic-heavy log parsing and static graph generation utilities in sync_tests, improving confidence in node/db-sync metrics extraction and report graph outputs.

Changes:

• Add unit tests for sync_static_graphs mode detection, db-sync normalization, and PNG output generation (node + dbsync).
• Add unit tests for node log metrics extraction (JSON tracer + human-readable tracer formats) and CPU/tip carry-forward behavior.
• Add unit tests for db-sync log metrics extraction (duration parsing + full epoch cycle) and for log_analyzer string detection / rollback detection / warnings.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
sync_tests/tests/test_sync_static_graphs.py	Covers JSON mode detection, db-sync normalization branches, and end-to-end PNG generation smoke tests.
sync_tests/tests/test_metrics_extractor_node.py	Adds coverage for node log parsing across tracer formats and CPU delta behavior.
sync_tests/tests/test_metrics_extractor_dbsync.py	Adds coverage for db-sync duration parsing and epoch/block parsing across a full epoch lifecycle.
sync_tests/tests/test_log_analyzer.py	Adds coverage for log string matching, rollback detection behavior, and warning emission.

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[mkoura]

Differentiate between framework tests and actual sync tests.

[OlufemiAdeOlusile]

Moved test_log_analyzer.py, test_metrics_extractor_dbsync.py, test_metrics_extractor_node.py, and test_sync_static_graphs.py into framework_tests/ (rebased onto main, which now has that directory from #165). These are pure unit tests of our own code with no live node/db-sync dependency.