Add Arize and Phoenix LLM observability skills (#1204)

* Add 9 Arize LLM observability skills

Add skills for Arize AI platform covering trace export, instrumentation,
datasets, experiments, evaluators, AI provider integrations, annotations,
prompt optimization, and deep linking to the Arize UI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Add 3 Phoenix AI observability skills

Add skills for Phoenix (Arize open-source) covering CLI debugging,
LLM evaluation workflows, and OpenInference tracing/instrumentation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Ignoring intentional bad spelling

* Fix CI: remove .DS_Store from generated skills README and add codespell ignore

Remove .DS_Store artifact from winmd-api-search asset listing in generated
README.skills.md so it matches the CI Linux build output. Add queston to
codespell ignore list (intentional misspelling example in arize-dataset skill).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Add arize-ax and phoenix plugins

Bundle the 9 Arize skills into an arize-ax plugin and the 3 Phoenix
skills into a phoenix plugin for easier installation as single packages.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix skill folder structures to match source repos

Move arize supporting files from references/ to root level and rename
phoenix references/ to rules/ to exactly match the original source
repository folder structures.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fixing file locations

* Fixing readme

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

skills/phoenix-evals/references/evaluators-code-python.md

@@ -0,0 +1,91 @@
+# Evaluators: Code Evaluators in Python
+
+Deterministic evaluators without LLM. Fast, cheap, reproducible.
+
+## Basic Pattern
+
+```python
+import re
+import json
+from phoenix.evals import create_evaluator
+
+@create_evaluator(name="has_citation", kind="code")
+def has_citation(output: str) -> bool:
+    return bool(re.search(r'\[\d+\]', output))
+
+@create_evaluator(name="json_valid", kind="code")
+def json_valid(output: str) -> bool:
+    try:
+        json.loads(output)
+        return True
+    except json.JSONDecodeError:
+        return False
+```
+
+## Parameter Binding
+
+| Parameter | Description |
+| --------- | ----------- |
+| `output` | Task output |
+| `input` | Example input |
+| `expected` | Expected output |
+| `metadata` | Example metadata |
+
+```python
+@create_evaluator(name="matches_expected", kind="code")
+def matches_expected(output: str, expected: dict) -> bool:
+    return output.strip() == expected.get("answer", "").strip()
+```
+
+## Common Patterns
+
+- **Regex**: `re.search(pattern, output)`
+- **JSON schema**: `jsonschema.validate()`
+- **Keywords**: `keyword in output.lower()`
+- **Length**: `len(output.split())`
+- **Similarity**: `editdistance.eval()` or Jaccard
+
+## Return Types
+
+| Return type | Result |
+| ----------- | ------ |
+| `bool` | `True` → score=1.0, label="True"; `False` → score=0.0, label="False" |
+| `float`/`int` | Used as the `score` value directly |
+| `str` (short, ≤3 words) | Used as the `label` value |
+| `str` (long, ≥4 words) | Used as the `explanation` value |
+| `dict` with `score`/`label`/`explanation` | Mapped to Score fields directly |
+| `Score` object | Used as-is |
+
+## Important: Code vs LLM Evaluators
+
+The `@create_evaluator` decorator wraps a plain Python function.
+
+- `kind="code"` (default): For deterministic evaluators that don't call an LLM.
+- `kind="llm"`: Marks the evaluator as LLM-based, but **you** must implement the LLM
+  call inside the function. The decorator does not call an LLM for you.
+
+For most LLM-based evaluation, prefer `ClassificationEvaluator` which handles
+the LLM call, structured output parsing, and explanations automatically:
+
+```python
+from phoenix.evals import ClassificationEvaluator, LLM
+
+relevance = ClassificationEvaluator(
+    name="relevance",
+    prompt_template="Is this relevant?\n{{input}}\n{{output}}\nAnswer:",
+    llm=LLM(provider="openai", model="gpt-4o"),
+    choices={"relevant": 1.0, "irrelevant": 0.0},
+)
+```
+
+## Pre-Built
+
+```python
+from phoenix.experiments.evaluators import ContainsAnyKeyword, JSONParseable, MatchesRegex
+
+evaluators = [
+    ContainsAnyKeyword(keywords=["disclaimer"]),
+    JSONParseable(),
+    MatchesRegex(pattern=r"\d{4}-\d{2}-\d{2}"),
+]
+```