Resolves each element of one block's emission to the block an author would recognise (ADR-0004 decision 5).

The compiler calls stamp/2 on a block's own emission the moment emit/2 returns it, before the children are spliced in. So each block stamps only what it wrote, every element ends up owned, and the spliced tree is total by construction rather than by a later sweep that would have to guess.

The three rules

• Default. An element belongs to the block that emitted it, with no config key.
• Role. An element whose id is a state id this block minted (StatifierBlocks.Compiler.StateId.unstate_id/1) takes that role, and everything inside it inherits the role until another state changes it. That is what puts s_blk_AUTH__running's <invoke> on blk_AUTH role running rather than on the block as a whole.
• Override. StatifierBlocks.Emission.attributed_to/2 moves an element and its subtree to another block and clears the role, which is the case decision 5 names: "attribution is a judgment, not a mechanism". StatifierBlocks.Emission.from_config/2 and attribute_from_config/3 set the config key that makes a finding the author's.

An attribution has to name a block in this document

A block type may only attribute an element to a block the compiler actually knows about - in practice, one of its own children, which is the only case decision 5 raises. stamp/2 takes the set of block ids that are legitimate targets and refuses anything else, because an owner naming a block the document does not contain is an unresolvable entry in a map whose whole purpose is resolving.