enhancement(tag_cardinality_limit transform): Add more fine grained controls tag cardinality (#25360)

* Implement per tag control in tag cardinality processor

* refactor(tag_cardinality_limit): simplify per-tag config to LimitOverride/Excluded enum

Replace the PerTagInner struct (with ambiguous optional fields) with a
PerTagConfig struct wrapping a PerTagMode tagged enum:

  - mode: limit_override + value_limit: N  — track with explicit cap
  - mode: excluded                          — opt out of tracking entirely

Removes PerTagInner, PerTagModeKind, and the old `excluded: bool` field.
The new shape is unambiguous: every per-tag entry must be one or the other.
YAML format is consistent with per-metric `mode: excluded`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* Make tag cardinality limit new public

* Update comments

* remove schema value limit min value enforcement and handle limit equals zero case

* add additional unit test covering zero limit case

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Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>