Problem

When a Choice state has a rule and a Default that both point to the same Next state (e.g., both go to "Pass"), the default's Assign and Output are incorrectly evaluated even when a choice rule actually matched.

This happens because _eval_state_output determined whether the default was selected by comparing self.default_state.state_name == next_state_name -- which is ambiguous when a matched rule and the default target the same state.

For example with this state machine:

{
  "Type": "Choice",
  "Choices": [
    {
      "Condition": "{% 'a' = 'a' and 'b' = 'b' %}",
      "Next": "Pass",
      "Assign": { "var_rule1": "rule 1" },
      "Output": { "rule1": "from rule 1" }
    }
  ],
  "Default": "Pass",
  "Assign": { "var_DEFAULT": "from default" },
  "Output": { "DEFAULT": "from default" }
}

The output would be {"DEFAULT": "from default"} instead of {"rule1": "from rule 1"}, because the default's Output/Assign overwrote the matched rule's values.

Fix

Instead of using next state name comparison (which breaks when they're the same), I push a boolean flag onto the environment stack to explicitly track whether a choice rule matched. _eval_state_output then pops this flag to decide whether to apply the default's Assign/Output.

Tests

Added test templates and test cases for both Assign and Output in Choice states where the matched rule and Default share the same Next target, with both condition=true and condition=false inputs.

Fixes #12301