Law 0 root (PR2a): the root's unit tests name no plane, transport or auth instance

[MattJackson]

Law 0 root lane, PR2a. This PR covers the root unit-test files that no open non-draft PR touches. Spec: BUSBAR-1.6.0.md l.172-182 (tests use kind-neutral doubles). Coordinator ruling: no golden pins of the default distribution; the 1.5.5 oracle cells prove customer bytes.

What changes

--help goldens. cli_help.txt and cli_help_without_flag_rows.txt are deleted. The tests that pinned them become invariants over the linked rows:

• every linked row lands in its block, in declaration order;
• the root's own text is all present, in order;
• a plane compiled out takes its rows with it and leaves the root's Flags: block alone.

Operator words (auth_bindings.rs). Assertions read the root's operator words instead of the spelled default:

• the default admin chain and identity providers;
• the reserved hook-name word space;
• the 1.4.x and 1.5.x migrations;
• the refusals naming the word.

Mint-needs RED (connector.rs). The test now reads every linked auth row's Statement and asserts each declared outbound need is operator infrastructure. It no longer names the plugin crate, and it fails if no linked row declares an outbound need.

connector_h2. The need's scheme is the admin plane's declared request/response wire.

linked_protocols.

• The absorbed event-stream set no longer carries a plane name; the fixture key is renamed.
• residual_none uses neutral paths instead of plane mounts.
• http is imported from the http crate.

Rewording only. Identifiers and prose in connector_h2, listener, listener_h2, plane_node, serve_framed, durability, kernel, linked, linked_auth, legacy, units_admin and src/tests.

kind-isolation (law0 rows lowered to the measure)

busbar axis	before	after
auth	49	46
hooks	1	0
instance:auth	24	15
instance:secret	35	33
plane	826	766
transport	224	205

The busbar × hooks [[cell]] row now covers nothing, so it is struck. These counts overlap #993's rows; rule 13 applies, and whichever lands second recomputes.

Not here

• Waiting on P3 FLIP-A2A: the a2a plane served through its door; busbar-a2a deleted (stacked on #778) #787 and FLIP-STREAMING: the streaming plane served through its door; busbar-voice deleted #503, which edit the same hunks: registry.rs and its fixtures (sealed_order, claims_per_plane, transport_fold), serve_tests.rs, gauntlet_kernel.rs.
• Waiting on PRs that touch the same hunks:
  • door_steps.rs: eight PRs.
  • The link_secrets test in linked.rs: row 166 PR2a: a disk-declared secret source resolves on the one disk lane at config time only #864 and row 166 PR2b: a program's environment secrets resolve at declaration and are held; a spawn resolves nothing #865.
• Root legs: door cells, door cells: plane doors state their root cells under links; no-cells RED; N/A held to the ledger (stacked on #787) #1006.
• Owned by other lanes:
  • mcp: tool_door_wire.txt.
  • decisions: door_listen.rs.
  • row-155 vendor lane: declared_credentials.rs.

merge-tree is clean against every open non-draft PR.

Replaced 1.5.5 pins, and where each now lives

replaced pin	1.5.5 bytes?	survives as
fixtures/cli_help.txt: the default build's --help	yes	(a) oracle golden cells cli|--help and cli|-h
fixtures/cli_help_without_flag_rows.txt: a build with no plane flag rows	no; 1.6.0-only shape (no such 1.5.5 build)	invariant
operator provider admin-tokens / principal admin	yes	(b) fixtures/operator_1_5_5.json (provider, principal), asserted equal. The provider is also covered by (a) admin.ops|GetInfo|ok (build.auth_modules = keys + the operator)
default_admin_auth_names / builtin_identity_providers	yes	(b) via the fixture's provider; also (a) admin.ops|GetInfo|ok
the reserved hook-name word space	yes	(b) fixtures/operator_1_5_5.json hook_word_space, the whole sorted set
the 1.4.x and 1.5.x migrations writing the operator word	yes	(b) the fixture's provider
unanswered_token / misplaced_token refusals	yes	(b) fixtures/operator_1_5_5.json, byte for byte

The Rust source names no auth module; the fixture is DATA.

[MattJackson]

#1028 also edits crates/busbar-plane-llm/src/codec/synth_rng.rs (fill_entropy takes a &dyn CodecHost), synth_rng_tests.rs, openai_chat/tests/handler_tests.rs (extract_usage call) and gemini+openai_chat float_usage_tests.rs (reader/writer calls take the test host). These are different hunks; note your branch's synth_rng.rs conflicts with predev's #869.