Create a lexicon entry from an unglossed morpheme

[imnasnainaec]

Close the dead end in the link flow: when searching the lexicon finds nothing, offer to add the morpheme to it.

Scope

Implement the port's createEntry and wire it to the "no match" state of the link affordance. Gated on the port's create capability.

This is the only path in the epic that writes to a lexicon. Everywhere else references are outbound only (#186, #194). That asymmetry is the reason this is its own item rather than a branch of the link flow.

Decisions this issue has to make

• What a draft entry contains when built from a morpheme — form, writing system, gloss, and morph type (see Handle morph-type indicators #130 for the morph-type indicators already specified). Nothing more; this is not an entry editor.
• When it writes — immediately on confirm, or on analysis approval. AssignmentStatus already distinguishes approved / suggested / candidate, so deferring is available if wanted.
• Whether a tier-2 write needs explicit confirmation. A real FW Lite lexicon is a curated deliverable, and creating entries from the interlinearizer is the one way this extension can put unreviewed data into it. A quiet auto-create is a consent problem, not just a data-hygiene one.
• What the created entry links back to — the new ref must carry provider provenance per Namespace lexicon refs by provider before any ref is persisted #225.

Blocked also on the epic's open question

"Create an entry" means different things in a full FW Lite lexicon and in a minimal one, and where a tier-1 lexicon persists is undecided. Everything else under this epic can proceed with that question open; this item cannot.

Blocked on

#228, plus the epic's tier-1 decision.