fix: emit loop captions during microflow describe

[hjotha]

Closes #443.

Summary

• Emit @caption for microflows.LoopedActivity during microflow describe.
• Use the same mdlQuote path as other activity captions.
• Add a focused regression test covering apostrophe and newline escaping in loop captions.

Validation

• make build
• go test ./mdl/executor -run 'TestEmitObjectAnnotations_LoopCaption|TestLoopCaptionPreserved|TestWhileLoopCaptionPreserved' -v
• make test
• make lint-go

[ako]

PR #444 Review — fix: emit loop captions during microflow describe

Clean, focused fix. Three lines of production code that mirror the adjacent ExclusiveSplit and InheritanceSplit handlers exactly. The write side (applyAnnotations in cmd_microflows_builder_annotations.go) already set Caption on LoopedActivity — this completes the roundtrip by emitting it on the describe side.

The unit test is good: covers apostrophe doubling and newline escaping through mdlQuote, which are the two failure modes that matter.

Minor

No doctype-level example for @caption on a loop

02-microflow-examples.mdl has @caption examples on activities and splits but nothing on a loop or while-loop statement. TestMxCheck_DoctypeScripts would never have caught this regression. Worth adding one microflow in that file with a loop that carries @caption, e.g.:

@caption 'Process each item'
loop $Item in $Items
  log info $Item/Name;
end loop;

This doubles as living documentation that @caption is valid on loop statements.

---

Otherwise looks good to merge.

[ako]

PR #444 Review — fix: emit loop captions during microflow describe

Clean, focused fix. Three lines of production code that mirror the adjacent ExclusiveSplit and InheritanceSplit handlers exactly. The write side (applyAnnotations in cmd_microflows_builder_annotations.go) already set Caption on LoopedActivity — this completes the roundtrip by emitting it on the describe side.

The unit test is good: covers apostrophe doubling and newline escaping through mdlQuote, which are the two failure modes that matter.

Minor

No doctype-level example for @caption on a loop

02-microflow-examples.mdl has @caption examples on activities and splits but nothing on a loop or while-loop statement. TestMxCheck_DoctypeScripts would never have caught this regression. Worth adding one microflow in that file with a loop that carries @caption, e.g.:

@caption 'Process each item'
loop $Item in $Items
  log info $Item/Name;
end loop;

This doubles as living documentation that @caption is valid on loop statements.

---

Otherwise looks good to merge.