feat: add Azure Policy AST types

[anakrish]

Add span-annotated AST types for Azure Policy conditions and rules, plus string utility enhancements for case-insensitive policy matching.

AST types (ast/):

• PolicyDefinition, PolicyRule with if/then/details structure
• Condition enum: field conditions, value conditions, logical combinators (allOf, anyOf, not), and count expressions
• Operator enums for all Azure Policy constraint operators (equals, contains, greater, matchInsensitively, etc.)
• Expr enum for field references, literal values, template function calls, and policy function invocations
• Value types with span tracking for error reporting

[Copilot]

Pull request overview

Adds foundational Azure Policy support types by introducing a span-annotated AST for policy definitions/rules/conditions and enhancing Azure Policy/ARM string comparison helpers for case-insensitive matching.

Changes:

• Introduces languages::azure_policy::ast with span-tracked nodes for policy rules, constraints, operators, values, ARM template expressions, and count.
• Updates Azure Policy string utilities to clarify/document casing semantics and adjusts key/value comparison helpers.
• Refactors Unicode case folding implementation to use icu_casemap::CaseMapper.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/languages/azure_policy/strings/mod.rs	Adds documentation pointer for casing semantics.
src/languages/azure_policy/strings/keys.rs	Adjusts ARM key comparison helpers (signature/param naming).
src/languages/azure_policy/strings/case_fold.rs	Refactors full Unicode case folding implementation using CaseMapper.
src/languages/azure_policy/mod.rs	Expands module docs, adds AST module export, and applies clippy allowances.
src/languages/azure_policy/ast/mod.rs	Adds top-level Azure Policy AST definitions (rules, constraints, operators, fields, etc.).
src/languages/azure_policy/ast/value.rs	Adds JSON/value/expression/count node types with span tracking.

Comments suppressed due to low confidence (1)

src/languages/azure_policy/mod.rs:12

• The crate-level #![allow(...)] here applies to the entire azure_policy module (including aliases and strings), potentially masking new warnings outside the AST code. Consider scoping these clippy allowances more narrowly (e.g., to ast or specific files) so unrelated code still benefits from linting.

#[allow(clippy::pattern_type_mismatch)]
pub mod aliases;
pub mod ast;
pub mod strings;

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.