Export TaskState and RunState enums from extension module

[Copilot]

The extension module had no public types for representing task and run states, forcing consumers to use string literals.

Changes

• New types module with TaskState and RunState enums

  • 6 variants each: Pending, Running, Sleeping, Completed, Failed, Cancelled
  • Matches database CHECK constraints from schema
  • Implements Display (enum → "lowercase") and FromStr (parse with validation)

• Public exports at crate root: absurd::{TaskState, RunState}

• Internal code updates to use enums instead of string literals

  • Updated checkpoint.rs, event.rs, run.rs, and claim.rs to parse state strings from database into enums for type-safe comparisons
  • States are converted back to strings when writing to database
  • Exhaustive match patterns with unreachable!() for impossible states

Usage

use absurd::TaskState;

// Type-safe state handling
let state = TaskState::Pending;
assert_eq!(state.to_string(), "pending");

// Parse with error handling
let parsed: TaskState = "running".parse()?;

Enables type-safe state handling in consuming crates and internally within the extension, while maintaining string compatibility with the database layer.

Original prompt

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This section details on the original issue you should resolve

<issue_title>export task enums from rust extension module</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes export task enums from rust extension module #33

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[bcho]

update existing code references to state string to use enum

[Copilot]

update existing code references to state string to use enum

Done in commit 88b66ba. Updated checkpoint.rs, event.rs, run.rs, and claim.rs to use TaskState and RunState enums instead of string literals for type-safe state handling. State values are read from the database as strings, parsed into enums for comparisons, and converted back to strings when writing to the database.