# Session handoff — 2026-06-09 (59)

Fifty-ninth handover. Continues from handoff-58 (H1a done). This
session did **three** distinct things, in order: (1) a
**tracking-integrity audit + reconciliation** of `requirements.md`
against the actual code; (2) a **partials sweep** closing V5, H3,
and a new V5a; (3) the big one — **T3 compound-PK foreign-key
references**, designed in **ADR-0043**, `/runda`-verified twice,
and implemented end-to-end across both surfaces.

## §1. State at handoff

**Branch:** `main`. **HEAD `4752ba2`.** 8 commits this session
(`28e7596` → `4752ba2`); push is the user's step.

**Tests: 2193 passing / 0 failing / 1 ignored** (lib 1578, it 423,
typing_surface_matrix 192; the 1 ignored is the long-standing
doc-test). **Clippy clean** (nursery, all targets).

**Requirements markers now:** `[ ]` 19, `[/]` 6, `[x]` 59,
`[~]` 11, `[-]` 3. (The `[/]` "partial / in progress" marker is
**new this session** — see §2.)

This session's commits:
```
4752ba2 feat: compound-PK foreign-key references — grammar + tests (ADR-0043)
b14f019 refactor: relationship model to column lists for compound FK (ADR-0043)
b688592 docs: ADR-0043 implementation-readiness notes from /runda DA pass
274e2b1 docs: ADR-0043 compound-PK foreign-key references (T3); accepted
1d898ad feat: V5a show relationship/index <name> detail views
757711f feat: H3 help <command> per-command detail + general reference
8dec784 feat: V5 show tables / relationships / indexes list commands
28e7596 docs: reconcile requirements tracking with verified code state
```

## §2. The tracking reconciliation (read this — it changes how you plan)

Planning off handoffs/`requirements.md` was **unreliable**: an
audit of all 35 `[ ]` items against the source found **~46 %
mis-marked**, overwhelmingly *under*-claimed (tab completion `I3`
and syntax highlighting `I4` were shipped but marked "not yet
implemented"). Root cause: the **binary legend** — a shipped
feature, a half-built one, and an untouched one all wore the same
`[ ]`.

Fix (commit `28e7596`): added a **`[/]` "partial / in progress"**
marker to the legend, with a dated reconciliation note. Re-marked:
- **7 shipped-but-`[ ]` → `[x]`:** S1, S4, S5, I1a, I3, I4, C1.
- **9 substantially-built → `[/]`** with explicit gap notes: S3,
  A1, V1, V2, V5, T3, H3, DOC1, X1.
- Fixed a **false `CLAUDE.md` claim** ("Tier 4 is wired") — no PTY
  tests exist; TT4 is spec-only.

**Discipline going forward:** move items `[ ]` → `[/]` → `[x]`;
keep the gap note current. Don't trust a marker without checking
the code — verify empirically.

## §3. The partials sweep (V5, H3, V5a)

Three small/medium, no-ADR partials closed (the others — V1, S3/V2,
A1, DOC1, X1 — need an ADR / output-model redesign / new features,
so were left `[/]`, see §5):

- **V5 `[x]`** (`8dec784`): `show tables` / `show relationships` /
  `show indexes` as one `Command::ShowList { kind }`; read-only
  worker `show_list`. 10 tests.
- **H3 `[x]`** (`757711f`): `help <command>` per-command detail
  (HELP node takes an optional `BarePath` topic; `note_help_topic`
  renders every command sharing the entry word) + `help types` +
  friendly unknown-topic pointer. 9 tests.
- **V5a `[x]`** (`1d898ad`): singular `show relationship <name>` /
  `show index <name>` detail — folded into `ShowList { kind, name:
  Option<String> }`. Raised + closed this session (it was the
  honest tracked home for V5's `[<name>]` clause).

## §4. T3 — compound-PK foreign-key references (the big one)

**ADR-0043** (`docs/adr/0043-compound-pk-foreign-key-references.md`,
Accepted + implemented). The open leg of T3: a FK that *references*
a parent's compound PK. The audit found single-column FK woven
through ~15–20 sites; it earned an ADR, not an inline build.

**Four forks, all user-confirmed at the recommended option:**
- **F-A** reference the parent's **full** PK (subset/UNIQUE-target
  OOS), matched **positionally** to an equal-length child list.
- **F-B** **house-style uniform lists, no migration** — the
  decisive simplifier: the user confirmed **back-compat is not
  required** (pre-release, no installed base), so `project.yaml`
  endpoints became `columns: [a, b]` (like `primary_key: [id]`),
  metadata `TEXT` cells store the list **comma-joined** (bare for
  single), and **no F3 migrator / version bump** was needed.
- **F-C** parenthesized DSL `from P.(a, b) to C.(x, y)` (single
  bare form unchanged).
- **F-D** bare table-level SQL `FOREIGN KEY (x,y) REFERENCES P`
  auto-expands to the parent's full PK when arities match.

**Implementation (two commits):**
- `b14f019` — **the refactor**: relationship model `String →
  Vec<String>` through all six layers (`AddRelationship` /
  `SqlForeignKey` AST, `RelationshipSchema`, metadata,
  `project.yaml`, `ReadForeignKey`, `RelationshipEnd`). **Single-
  column behaviour preserved** (one-element vecs); the existing
  single-column relationship suite was the regression net. This is
  the safe green checkpoint.
- `4752ba2` — **the grammar + tests**: multi-column parsing on both
  surfaces (`AR_PARENT_COLS`/`AR_CHILD_COLS` Choice in `ddl.rs`;
  `FK_*_COL_LIST` Repeated in `sql_create_table.rs`;
  `consume_fk_reference` + the table-level/ALTER parsers collect
  lists). Executor: `resolve_fk_parent_columns` (F-A validation +
  F-D auto-expand + arity), per-pair `check_fk_type_compat`,
  `schema_to_ddl` multi-column emission, `pragma_foreign_key_list`
  read **grouped by `id`, ordered by `seq`** (positional pairing),
  auto-name joins lists, `--create-fk` per-column, multi-column
  teaching echo. 12 tests in `tests/it/compound_fk.rs`.

**`/runda` ran twice** (once on the ADR pre-build, once on the
finished code). The post-build pass **found 3 coverage gaps and
they were closed**: save→rebuild round-trip (the riskiest — proves
comma-encode/decode + yaml + FK reconstruction survive a text→db
rebuild), undo (one step), per-pair type-mismatch.

**Two residuals, confirmed non-blocking (noted in code):**
1. inline `col REFERENCES P(a,b)` gives a *generic* arity error,
   not the ADR's tailored "use the table-level form" pointer.
2. a compound-FK *violation*'s friendly error names only the first
   column pair (the ADR-0019 facts model is single-column).
Both are messaging-only; FK correctness/enforcement is unaffected.

**Process note (a real scare):** a broad regex script over test
files (to wrap `add_relationship` call args + struct fields in
`vec![]`) **over-reached into lib structs** it shouldn't have
(`RelationshipSelector::Endpoints`, `FailureContext`/
`TranslateContext` — all deliberately single-column), briefly
breaking the lib build. Recovered by reverting those specific
sites. Lesson: scripted edits across `src/` are dangerous when a
field name (`parent_column`) is shared between the struct you're
migrating and ones you're not — prefer compiler-guided manual fixes
or scope the script tightly.

## §5. Remaining open landscape (now trustworthy)

**Still `[/]` partial (need design/ADR or are larger):**
- **V1** relationship line-art visualization — **needs a
  visualization ADR** (the most-requested deferred item).
- **S3 / V2** multi-result tabs — output-model redesign (single
  buffer → tab abstraction).
- **A1** app-commands — blocked on `seed` (SD1) + `hint` (H2),
  both unbuilt features.
- **DOC1** reference docs — writing effort.
- **X1** logging density — broad/mechanical (~25 `tracing` sites
  today; `CLAUDE.md` wants "log liberally").

**`[ ]` not started:** H2 `hint`, SD1 `seed`, C4 m:n, B3
query-timeout, I1 multi-line, I1b readline, I5 cancellation, TT5
CI, TT4 PTY (spec-only), D1–D3 distribution, NFR-1…7.

## §6. Next job — candidates

No forced next step. By readiness:
1. **V1 relationship visualization** — design-first (its own ADR).
   The user has flagged it repeatedly; it's the prominent open
   design item.
2. **X1 logging** — mechanical, no ADR; brings the codebase to the
   `CLAUDE.md` "log liberally" bar.
3. **TT5 CI** — test infra is solid (2193 green); no workflow yet.
4. The two T3 residuals (§4) — small messaging polish if they bug
   you.

## §7. How to take over

1. Read handoffs 57 → 58 → 59, then `CLAUDE.md`,
   `docs/requirements.md` (now with the `[/]` marker + the §2
   reconciliation note), `docs/adr/README.md`.
2. **For relationships/FK: read ADR-0043.** The model is list-based
   (`Vec<String>`); single-column is the one-element case.
3. Codebase on `main` at `4752ba2`, clean, 8 commits unpushed.
4. Process pins that paid off: **verify the tracker against code,
   don't trust the marker**; **escalate genuine forks** (the four
   ADR-0043 forks were the user's); **`/runda` after planning AND
   after implementation** (the post-build pass found 3 real gaps);
   **scope scripted edits tightly** (§4 scare). Commits
   user-confirmed, append-only, no AI attribution.