2.2.78

## What's Changed
* [OPIK-8468] [QA] test: cover the failed playground run error state (from #8445) by @CometActions in https://github.com/comet-ml/opik/pull/8471
* [OPIK-7791] [QA] Proposed e2e specs from the 2.2.71 → 2.2.72 release exploration: dataset-item field mappings by @CometActions in https://github.com/comet-ml/opik/pull/8440
* [OPIK-7791] [QA] Proposed e2e specs from the 2.2.73 → 2.2.74 release exploration by @CometActions in https://github.com/comet-ml/opik/pull/8467
* [issue-8395] [SDK] fix: honour explicit empty rule sets in PromptInjection and Tone by @CodeWithMoin in https://github.com/comet-ml/opik/pull/8427
* [issue-8383] [SDK] fix: correct the worked examples in the distribution metric docstrings by @feiiiiii5 in https://github.com/comet-ml/opik/pull/8384
* [issue-8362] [SDK] fix: keep streamed Mistral tool calls apart when index is not sent by @feiiiiii5 in https://github.com/comet-ml/opik/pull/8363
* [OPIK-7724] [HELM] Add ClickHouse cold-tier enable migration job by @GuySaar8 in https://github.com/comet-ml/opik/pull/7767
* [NA] [SDK] fix: flatten whitespace before fastText language detection by @anishmehta24 in https://github.com/comet-ml/opik/pull/8493
* [OPIK-8198] [FE] alerts: triggers first, suggested names, and inline webhook testing by @aswynz in https://github.com/comet-ml/opik/pull/8099
* [DND-1626] [HELM] fix: honor minAvailable/maxUnavailable of 0 in the PDB template by @GuySaar8 in https://github.com/comet-ml/opik/pull/8490
* [DND-1735] [BE] Add minmax skip index on trace_threads.created_at by @GuySaar8 in https://github.com/comet-ml/opik/pull/8452
* [OPIK-6907] Apply ClickHouse merge/reclaim settings cluster-wide by @GuySaar8 in https://github.com/comet-ml/opik/pull/8487
* [NA] [SDK] fix: validate string output in Contains, LevenshteinRatio and RegexMatch by @anishmehta24 in https://github.com/comet-ml/opik/pull/8501
* [issue-8393] [SDK] fix: report every jury vote in judge_scores by @feiiiiii5 in https://github.com/comet-ml/opik/pull/8394
* [OPIK-8274] [SDK] perf: read experiment items 33x faster — 2,000 per page, concurrent, no model parsing by @thiagohora in https://github.com/comet-ml/opik/pull/8491
* [OPIK-8274] [SDK] docs: say what the experiment read's wave-size estimate assumes by @thiagohora in https://github.com/comet-ml/opik/pull/8504

## New Contributors
* @CodeWithMoin made their first contribution in https://github.com/comet-ml/opik/pull/8427

**Full Changelog**: https://github.com/comet-ml/opik/compare/2.2.77...2.2.78