batch: runner core — types, Submit with idempotency and caps, Status, Touch, Cancel

New package internal/batch holding the runner core with no workers yet (task 03
adds them; until then every job stays queued, so a queued job counts as live for
the caps). batch.go defines the public surface: Options/Target/Result/TargetError,
FetchFunc, Job/TargetStatus, Hooks and Config with its defaults (TTL 24h, 32
targets/job, 1 job/caller, 8 total, worker clamped to 2, 64 MiB, 2 s / 10 m retry).

Submit runs in the given order: empty → ErrNoTargets; idempotency via hex SHA-256
of `c.Name + NUL + json.Marshal(targets)` (a live BatchJobByIDem hit returns the id
reused, touching no caps); then TargetsPerJob / JobsPerCaller / JobsTotal; then it
stores the job queued (random 16-byte hex id, CreatedAt = Lease = now) and its
targets (pending, Options = json of t.Options) before returning. The submitting
caller is held in memory keyed by job id, never persisted (jobs never resume after
a restart). Status maps the rows and decodes Result from the result column without
writing; Touch moves the lease; Cancel sets a queued job cancelled at once and
leaves its targets pending; Close is idempotent. Store errors are Warn-logged with
the job id, never a URL or host.

Co-Authored-By: ornith-1.5-35b-a3b <ornith-1.5-35b-a3b@llama.cpp.invalid>

docs/implementer-log.md

@@ -17,7 +17,8 @@ One row per task session that ends in a commit. Newest last.
 | p5b/03-api | 2026-09-26 | done | 1 | gate: ok | none | The digest now answers long documents itself (task 02), so the API's refusal limit is only a safety cap: `DefaultPDFMaxQuestionChunks` 200→5000 in `internal/api/pdf.go` (the 422 message text unchanged, still "document too long for question (N chunks); use grep or pages"). In `v1fetch` (`internal/api/api.go`) the digest-meta map gains `"retrieval": dr.Retrieval` and `"embedded": dr.Embedded` next to `chunks_used`/`chunks_total`, only when the digest ran without a fallback. Copied the two given tests byte-identical from the plan — the replacement `pdf_test.go` is now the protected one and asserts `DefaultPDFMaxQuestionChunks == 5000`; `pdf_retrieval_test.go` asserts the first long-doc question returns `retrieval=bm25`, `embedded=0`. README PDF section: a long-doc question is answered first from BM25 (`retrieval: "bm25"`) while its chunks embed in the background and hybrid on later questions, plus the 5000-chunk cap. One sentence added to `skill/SKILL.md`. All api tests pass under `-race -count=3`; make gate ok; given files byte-identical. |
 | p5c/01-extract-api | 2026-09-26 | done | 1 | gate: ok | none | `POST /v1/extract` answers a PDF posted in the body like `/v1/fetch` answers the same PDF by URL, nothing fetched. `internal/api/extract.go`: auth via `caller`; `io.ReadAll` of the body (a `*http.MaxBytesError`→413 "too large (>N MB)", empty→400); `clean.Kind` must be "pdf" else 415; query `pages`/`grep`/`question`/`mode` (digest when a question is set, else clean; other→400). Content-addressed cache: `hash="sha256:"+HashBody(body)`, `key=PDFKey("upload:"+hash, callerClass)`; a `GetPDF` hit rebuilds the doc via `pdfFromEntry` with `cached:true` + `PDFCacheHit` and no child (bypasses the TTL/revalidation that `pdfFromCache` does, so identical content is extracted once); a miss builds a synthetic `fetch.Resource{URL:"upload",...}` and runs `extractPDF`+`storePDF`. Bad pages/grep→400 via `writeFetchErr`, the chunk limit→the same 422 as `v1fetch`, extraction errors→`pdfError` via `writeFetchErr`. Envelope mirrors the PDF fetch path (`content`/`mode`/`untrusted`/`warnings`/`sizes`/`timings`/`pdf`/`digest`); `source` is `{"kind":"upload","hash","bytes","cached","fetched_at"}` with no `url` key; no Honcho context for uploads; one log line "extract" with caller/bytes/pdf_pages/mode/cached. `internal/api/api.go` scoped to the rule-1 changes: `DefaultPDFMaxUpload` const (100 MiB), `PDFMaxUpload int64` Server field, the `POST /v1/extract` route in `New`, and `ServeHTTP` (per-path upload cap instead of the 64 KiB JSON limit, and `/v1/extract` added to the `requestDeadline` switch). The `pdfMaxUpload()` field-or-default resolver lives in extract.go. Given test byte-identical; all api tests pass under `-race -count=3`; make gate ok. |
 | p5c/02-extract-cli | 2026-09-26 | done | 1 | gate: ok | none | `sift extract <file.pdf>` uploads a local PDF to `/v1/extract` and prints the answer exactly as `sift fetch` does. `cmd/sift/extractcmd.go`: `extractOpts` + `parseExtractOpts` (reuses `splitAroundPositional` with `extractValueFlags` mode/pages/grep/question, one positional file, `--json`), `extractURL` builds `base+"/v1/extract"` with `url.Values` set only for the options that are set and `mode=digest` when a question is given and no mode — values are URL-encoded so a grep like `a b&c` survives round-trip; `extractMain` reuses `loadClient`, `stat`s the file and refuses >100 MiB before uploading (exit 3, matching the server's 413→exitFor), then `http.NewRequest` with the `*os.File` as the streaming body and `ContentLength` set (no second in-memory copy), `Content-Type: application/pdf` + bearer, and the same error/exitFor path as fetch; success prints `content` (or the `--json` envelope). `main.go`: `case "extract"` and one help line. README: extract line in the CLI block plus a sentence; SKILL.md: a PDF-on-disk bullet in the PDFs section. Given test byte-identical; all cmd/sift tests pass under `-race -count=3`; make gate ok; `bin/sift extract` prints the usage line. |
-| p6/01-batchstore | 2026-09-26 | done | 1 | gate: ok | none | Storage-only batch store in `internal/dcache` (new `batch.go`; schema added to `Open`; `BatchH`/`BatchM` counters added to `DB`). `CreateBatchJob` stores as given. Reads never write the lease: `BatchJob`, `BatchTargets` and the counts are pure, so exact lease values hold after a read. `BatchJobByIDem` returns the newest `(caller,idemKey)` job with `lease+ttl>now` and status queued/running/done/partial; failed/cancelled never reused. `PutBatchTargets` inserts in order; `BatchTargets` returns idx order with NULLs as nil pointers. `UpdateBatchTarget` bumps lease to `now`, increments `targets_done` exactly once per target entering done/failed (previous-status check prevents re-write double-count), and adds `len(result)` to `nbytes` when a result is written — all in one tx. `SetBatchJobStatus`/`TouchBatchJob` set lease; `SweepBatch` deletes by `lease+ttl<=now` with its targets and returns the job count; `EvictBatchOldest` evicts whole non-live jobs oldest-lease-first (never a queued/running one) until `BatchNbytes()<=maxBytes`; `MarkInFlightFailed` fails queued/running on restart; `BatchNbytes` sums job nbytes, kept out of `Size()`. Accessors return `(v,bool)`/`error`, count misses in `BatchM`, reuse `ClassFleet`/`ClassRestricted`. A first pass failed `TestBatchIDemLookup` because I forgot `.Scan(&id)` on the `QueryRow` (the un-scanned `*sql.Row` was always non-nil, so the method always missed); fixed and verified. All dcache tests pass under `-race -count=3`; make gate ok; given file byte-identical. |
+| p6/01-batchstore | 2026-09-26 | done | 1 | gate: ok | none | Storage-only batch store in `internal/dcache` (new `batch.go`; schema added to `Open`; `BatchH`/`BatchM` counters added to `DB`). `CreateBatchJob` stores as given. Reads never write the lease: `BatchJob`, `BatchTargets` and the counts are pure, so exact lease values hold after a read. `BatchJobByIDem` returns the newest `(caller,idemKey)` job with `lease+ttl>now` and status queued/running/done/partial; failed/cancelled never reused. `PutBatchTargets` inserts in order; `BatchTargets` returns idx order with NULLs as nil pointers. `UpdateBatchTarget` bumps lease to `now`, increments `targets_done` exactly once per target entering done/failed (previous-status check prevents re-write double-count), and adds `len(result)` to `nbytes` when a result is written — all in one tx. `SetBatchJobStatus`/`TouchBatchJob` set lease; `SweepBatch` deletes by `lease+ttl<=now` with its targets and returns the job count; `EvictBatchOldest` evicts whole non-live jobs oldest-lease-first (never a queued/running one) until `BatchNbytes()<=maxBytes`; `MarkInFlightFailed` fails queued/running on restart; `BatchNbytes` sums job nbytes, kept out of `Size()`. Accessors return `(v,bool)`/`error`, count misses in `BatchM`, reuse `ClassFleet`/`ClassRestricted`. A first pass failed `TestBatchIDemLookup` because I forgot `.Scan(&id)` on the `QueryRow` (the un-scanned `*sql.Row` was always non-nil, so the method always missed); fixed and verified. All dcache tests pass under `-race -count=3`; make gate ok; given file byte-identical.
+| p6/02-runner-core | 2026-09-26 | done | 1 | gate: ok | caller-cleanup hand-off to task 03 | Runner core in new internal/batch with no workers (task 03 adds them; jobs stay queued, so a queued job counts as live for the caps). Public surface in batch.go: Options/Target/Result/TargetError, FetchFunc, Job/TargetStatus, Hooks and Config with defaults (TTL 24h, 32 targets/job, 1 job/caller, 8 total, worker clamped to 2, 64 MiB, 2 s/10 m retry). Submit runs the given order — empty→ErrNoTargets, idempotency via hex SHA-256 of `name+NUL+json.Marshal(targets)` (a live hit returns the id reused, touching no caps), then TargetsPerJob/JobsPerCaller/JobsTotal caps, then stores the job queued (random 16-byte hex id, CreatedAt=Lease=now) and its targets (pending, Options=json of t.Options) before returning so a queued job is live; the submitting caller is held in memory by job id, never persisted. Status maps rows and decodes Result without writing; Touch moves the lease; Cancel sets a queued job cancelled at once and leaves its targets pending; Close is idempotent. Store errors are Warn-logged with the job id, never a URL/host. | |
 
 ## P5a review (owner, 2026-09-26)