Retire the node_grounding_frontier_note prose row (DESIGN §4c)

[gunbai-bot]

Part 2 of node adhoc-a672d4e5-35c, split out at neat-boar-16's direction so it is not held by part 1.

v2.compiler.infer node_grounding_frontier_note was a data …: String prose row, which §4c classifies as unclassified prose.

• Rationale (why GroundingNotDerived exists, and the self-typing defect it replaced) → a // annotation on v2.compiler.inferred_tree NodeGrounding, the type whose arm is the frontier.
• Typed facts: the per-rule descriptions duplicated each rule function's own annotation, so they were dropped. The "6 of 12 kinds" count was transcribed and stale, and is not re-homed (§6: name the instrument; the counted infer_grounding_not_derived diagnostic is that instrument). The dissolve trigger stays with the compile_door_cause_ownership flip_triggers, which now cite NodeGrounding.
• The row is deleted, and every citation (the doc_graph_roots DeclarationRef, the flip_triggers, comments, plan docs) is repointed to the symbol.

No behavior change. Nothing had read the row as data: its only consumer was the doc-bind DeclarationRef. with Claude Code

Rework (review from neat-boar-16)

• The retirement condition is typed: v2.workflow.compile_door_cause_ownership node_grounding_frontier_retirement (FrontierRetirement, the four grounding causes). It replaces the retirement prose in the flip_trigger strings.
• gunbc.witness_v2_native_route native_route_frontier_retirement_standing consumes it. It joins the causes to the route's observed population (file refusals plus refused members) and returns Open { remaining }, Retired, or CauseUnowned. The admission clause FrontierRetirementCausesUnowned refuses when a retirement cause has no fatal-grain ownership row.
• The NodeGrounding // keeps only the historical self-typing rationale. The plan docs no longer carry kind counts. The root-partition bind now points at the producer, v2.compiler.infer inferred_facts_not_derived.
• Claims in src/v2/test/v2_native_route_test.dag:
  • discriminating: Open with exactly 2 across both populations
  • positive control: Retired
  • red: an unowned cause stands Unowned
• They are being run on srv1 because BuildBuddy runners page-thrash on this module.

Named frontier, deliberately not a gate: no admission clause refuses when the grounding frontier reaches zero, because that would be a wall about a goal, not a defect. Nobody has measured today's native-route count. Trigger: once that count is measured (the seven canary gives it), retirement becomes a typed standing that consumers read, still not a gate.

🤖 Generated with Claude Code

[gunbai-bot]

srv1 claim_batch receipt at 0aa1189 (run by neat-boar-16), v2.test.v2_native_route: PASS the_grounding_frontier_is_open_over_both_populations, PASS the_grounding_frontier_retires_when_no_cause_is_observed, PASS a_retirement_over_an_unowned_cause_is_not_retired, PASS the_refusal_tally_counts_each_refusal_once_at_fatal_grain. BuildBuddy page-thrashed on this module, so srv1 was used. — sent from witty-heron-282