@cc [owner:Yassimba] authoring.keyed-map-sites
Applies only to `DocumentBlock` in `tree/document.py`.

For a declared mapping of names to model values, source traversal associates each value with its declared
model and full source pointer. Field lookup works inside incomplete mapping entries without treating an
entry name as a model field or selecting a backend-specific schema.

@cc [owner:Yassimba] datasource.document-validation
Applies only to `ValidatedDocument.build` in `read/validate.py` when it validates a Datasource.

Datasource Document Validation checks supplied fields and each shared-plus-profile combination without
reading environment values or opening connections. It does not reject incomplete shared fields before
considering their sibling profiles. Invalid fields or credential combinations in inactive profiles remain
document errors. Checks that require concrete environment values run after resolution; supported typed
environment references remain valid authored inputs.

@cc [owner:Yassimba] datasource.authored-roundtrip
Applies only to `FormatCodec.encode` in `codec.py` when it encodes a Datasource.

Encoding a Datasource preserves authored references, profile names, supplied-versus-omitted connection
fields, and existing residue behavior. It does not write effective merged values, unrequested connection
defaults, resolved credentials, or driver declarations into YAML.

@cc [owner:Yassimba] tree.position-owner
Applies to every module in `formats/`.

Only `place` in `tree/declared.py` records the standard position of a format model, and only
`ObjectNode.write_default` derives the write default of a key. No code writes a standard position or a
write default onto a model class or onto a `FieldInfo` or its `CodecBinding`.

@cc [owner:Yassimba] tree.position-inheritance
Applies only to `position_of` in `tree/nodes.py`.

A model without its own position takes the position of its nearest base class that has one. On one
class, the `node=` class keyword wins over the position that `place` found. A model with no such
class in its bases has no position.

@cc [owner:Yassimba] tree.write-default-precedence
Applies only to `ObjectNode.write_default` in `tree/nodes.py`.

A key that the Starter Document does not write has no write default. Otherwise the authored
`starter="..."` text wins over the default of the standard. A standard default that is not a string
gives no write default.

@cc [owner:Yassimba,test:test_selection_decision_table_at_compiled_grammar_seam] check-entry.one-selector
Applies only to `CompiledGrammar.entry_model_for` and `CompiledGrammar.candidates` in `read/check_compile.py`.

Only these two methods pick the member of an authored check entry. Decode, validation, and the
editor ask them; no other code reads `form_selector` or `open_models` to pick a form.

@cc [owner:Yassimba,test:test_entry_sites_decision_table_at_compiled_grammar_seam_match_the_declared_grammar] check-entry.form-for-sites
Applies only to `CheckFormGrammar.form_for` in `checks/grammar.py`.

`form_for` is the one method that picks the form of an entry. The site helpers of the grammar
(`type_name_of`, `type_pointer`, `threshold_pointer`) ask it, never `entry_model_for`. A compiled
grammar changes `entry_model_for` to give a member, so its inherited helpers give the same sites
as the declared grammar.

@cc [owner:Yassimba,test:test_unknown_form_capability_at_grammar_seam_names_the_nearest_form] check-entry.unknown-form
Applies only to `CheckFormGrammar.unknown_form` in `checks/grammar.py`.

An entry whose selector names no form gives one UNTRANSLATABLE finding. Its help names the
nearest form, or lists every form when none is near.

@cc [owner:Yassimba,test:test_describe_arguments_decision_table_at_fix_seam_writes_front_matter_that_loads] check-type-document.describe-arguments-loads
Applies only to `_describe_arguments_fix` in `check_templates.py`.

Each undeclared-argument warning of one file offers the same repair. The repair describes every
undeclared argument inside the front-matter comment, and makes the comment when the file has none.
The file that the repair writes loads with no finding.
