Support both candidate info YAML formats

[npolshakova]

Problem

Candidate info metadata can be written as either a YAML mapping:

info:
  employer: Example
  slack: example

or a sequence of one-key mappings:

info:
  - employer: Example
  - slack: example

The low-level parser has tests for both forms from #114, but support is not end-to-end:

• Election.candidate() assumes the sequence form and calls .keys() on each item. A mapping therefore raises an exception while rendering the candidate profile, as seen in Links to candidate bios are not working for 2026 Kubernetes Steering Election #144.
• scripts/validate-bios models info as []map[string]string, so the validator on main also does not accept both forms.

Desired behavior

• Normalize mapping and sequence forms before candidate fields are rendered.
• Update the candidate bio validator to accept both forms.
• Validate fields generically against show_candidate_fields.
• Add model/controller regression tests that render candidate profiles using both forms.
• Keep the documented/template format consistent with the chosen canonical representation.

References

• Production failure: Links to candidate bios are not working for 2026 Kubernetes Steering Election #144
• Parser-only compatibility tests: Add tests for yaml object format #114
• Profile-rendering assumption:

  elekto/elekto/models/meta.py

  Lines 163 to 180 in da4c19c

  	def candidate(self, cid):
  	path = os.path.join(self.path, 'candidate-{}.md'.format(cid))
  	if not os.path.exists(path) or not os.path.isfile(path):
  	return F.abort(404)
  	md = open(path).read()
  	candidate = utils.extract_candidate_info(md)
  	candidate['key'] = cid
  	candidate['description'] = utils.parse_md(
  	utils.extract_candidate_description(md), False)
  	# return only the candidate optional fields that are listed in show_candidate_fields
  	# unfilled fields are returned as '' so the label still displays
  	candidate['fields'] = self.showfields()
  	for info in candidate['info']:
  	field = list(info.keys())[0]
  	if field in candidate['fields']:
  	candidate['fields'][field] = info[field]
  	return candidate

• Validator type assumption:

  elekto/scripts/validate-bios/main.go

  Lines 37 to 41 in da4c19c

  	type CandidateHeader struct {
  	Name string `yaml:"name"`
  	ID string `yaml:"ID"`
  	Info []map[string]string `yaml:"info"`
  	}

• Related Kubernetes metadata compatibility change: Update candidate bios format kubernetes/community#9116

[jberkus]

Yeah, I think this is the right way forward; there's no good reason to force folks to use the - format.