feat(linter): add GL046-GL049 rules, AND-group support, and GL032 fix

- GL046: validate image/service pull_policy values (always, if-not-present, never)
- GL047: error when a variables.options default value is not in the options list
- GL048: error on unrecognised trigger.forward keys
- GL049: validate rules[n].allow_failure (bool or {exit_codes:} map)
- Parse and evaluate workflow.rules/job.rules nested-array AND-groups; crash
  on !!seq nodes is fixed; all members of a group must match for it to fire
- Add workflow.name and workflow.auto_cancel fields to Workflow struct
- Fix GL032 false positive: variables declared in any workflow rule's variables:
  block no longer trigger an undeclared-variable warning in sibling workflow
  rule if: expressions
- Add Windows ARM64 release build target (task build-windows-arm64)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Taskfile.yml

@@ -117,6 +117,8 @@ tasks:
         ignore_error: false
       - cmd: ./{{.BINARY}} check testdata/rules_needs_invalid.yml
         ignore_error: true
+      - cmd: ./{{.BINARY}} check testdata/nested_rules.yml
+        ignore_error: true
       - cmd: ./{{.BINARY}} explain GL007
         ignore_error: false
       - cmd: ./{{.BINARY}} explain gl042