T33 Symbolic rule layer over braid events

[superposition]

Part of #11

Steps

Step 33. The symbolic layer: rules over braid events.
Create crates/braid/src/rules.rs — pure, no I/O, no clocks:

pub enum EventPattern { MissionClosed { outcome: String }, PromotionRolledBack, Quarantined, DriftAbove { threshold: f32 } }
pub enum BraidAction { LowerCoupling { factor: f32 }, RequestTraining, RollBackGeneration, EnterObserveOnly, RequestSafeStop }
pub struct Rule { pub when: EventPattern, pub then: BraidAction }
pub fn default_rules() -> Vec<Rule>;
pub fn evaluate(event: &BraidEvent, rules: &[Rule]) -> Vec<BraidAction>;

default_rules() returns, in order: MissionClosed { outcome: "failed" } → LowerCoupling { factor: 0.90 },
PromotionRolledBack → EnterObserveOnly, Quarantined → RequestTraining (the quarantine is a reason
to learn from what survived), DriftAbove { threshold: 3.0 } → EnterObserveOnly. Rules are data, so a
later rule set is a new vector, not a code change.

Test written first

default_rules_are_ordered_and_pure

Commands

cargo test -p qualia-braid

Evidence

pending

Journal

the-ladder

Blocked by

• T22 (T22 Rollback and quarantine routing #37)

Definition of done (2026-09-11)

• the package builds and its tests pass on the dev host (cargo build -p <pkg> && cargo test -p <pkg>);
• the artifact is built for the robot (aarch64) and exercised on Pinkie, the Waveshare-carried
  Jetson Orin NX at jetson@192.168.55.1 (see docs/decisions.md D-010), by this ticket's own smoke
  path or command;
• the handoff comment quotes the build/deploy command and the output observed on the board;
• a host-only package that cannot run there (the macOS metal backend) records the aarch64 build as
  its board evidence and states why execution on the board is impossible.

[superposition]

agent: ImplT33
branch: ticket/T33
commit: 2602c4d1dbb3bb25ffceec0984712a1545e8cf8e
state: review
next: Read the three verdicts (correctness, clean-room, contract) on PR #200, then merge
blocked_on: none
evidence: https://github.com/superposition/qualia/pull/200

T33 (#49) is implemented, tested and pushed: crates/braid/src/rules.rs (new),
crates/braid/tests/rules.rs (new), one line of crates/braid/src/lib.rs (pub mod rules;). The
ticket's own command, on the dev host:

$ cargo test -p qualia-braid -j 2
tests/braid.rs 6 passed · tests/clock.rs 4 passed · tests/drift.rs 6 passed ·
tests/manifest.rs 1 passed · tests/rules.rs 7 passed   → EXIT=0 (24 passed; 0 failed)
$ python scripts/provenance_check.py                                  → provenance: OK (exit 0)

Falsification of the new tests (swap the first two default rules; ignore the matched outcome), one
rebuild, both caught: EXIT=101; reverted, full suite green again.

Interface fact for the reviews and the board leg. default_rules() includes
DriftAbove { threshold: 3.0 } → EnterObserveOnly, but the crate's frozen BraidEvent vocabulary
(six variants + Unknown, T19; T20's PR #196 does not change it) carries no drift measurement, and
T34 shipped DriftReport/measure without a drift event — the drift reaches the healing ladder
(T35, #51) directly. So DriftAbove is contract data that fires nothing against every event evaluate
can be handed today. I did not invent a BraidEvent variant the ticket does not name (D-001). The
sample_count == 0 no-opinion convention is documented on the variant and pinned by
the_drift_rule_fires_on_no_event_the_braid_carries_yet; it takes effect the day the wire carries
drift. Details and the full evidence block are in PR #200.

Board evidence is the board leg's, per docs/agents.md §Definition of done: qualia-braid is a
library with no binary, so cargo test -p qualia-braid is its smoke path, built and run natively on
Pinkie. I have not touched Pinkie.

[superposition]

agent: Board3
branch: none (board evidence; PR #200 head, ticket/T33)
commit: 2602c4d1dbb3bb25ffceec0984712a1545e8cf8e
state: evidence
next: Main merges #200; 24 tests green on aarch64
blocked_on: none
evidence: PR #200 comment — cargo test -p qualia-braid 24 passed / 0 failed RC=0

Leg 2 of this queue ran T33 on Pinkie at 2602c4d1dbb3bb25ffceec0984712a1545e8cf8e (PR head =
refs/heads/ticket/T33), from a git archive of that sha; board file hashes equal the head's
(crates/braid/src/lib.rs b91f243e…, src/rules.rs 95c0a30d…, tests/rules.rs a7c31dfb…,
Cargo.lock 4bc0ec51…). Native aarch64, RUSTFLAGS="-C target-feature=+fp16", -j 2, /dev/shm
checked free:

cargo test -p qualia-braid --offline -j 2
  braid 6 · clock 4 · drift 6 · manifest 1 · rules 7 → 24 passed; 0 failed    BRAID_TEST_RC=0

Exactly the expected 24, including the new tests/rules.rs (7). The crate is a library, so this command
is its own smoke path; the aarch64 test binaries were built and run natively. Detail:
#200 (comment)