chore(spike): recover the /bygge toolchain from tmpfs (#28)

analyze_srt.py, build_page.py and transcode.yaml produced the /bygge
prototype. They were sitting in a session scratchpad on tmpfs, one reboot
from gone, while spike issues #29-#31 were written as if they had to be
built from scratch.

Committed as found, defects documented rather than fixed: max_tokens=6000
truncates anything past ~6 minutes of audio, the page title is hardcoded,
and the schema still carries fields no consumer renders.

The four-check validator is the part worth keeping — the coverage-gap and
Swedish-number-grounding checks catch errors that timestamp and citation
checks structurally cannot.

Real transcripts and analyses stay out: this repo is public and the
recordings are a named person discussing a client's project. Only the
synthetic fixture is committed, which exercises all four checks with no
model call.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BeAp5LTscnz2W7Ubt4eJ6m

scripts/spike-media/README.md

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+# spike-media — the `/bygge` toolchain, recovered
+
+Throwaway spike tooling for #28 (upload → transcript → takeaways). Committed
+because it was found in `tmpfs` one reboot from gone, not because it is finished.
+
+Nothing here is wired into tapir. No database, no HTTP handler, no ADR.
+
+## What produced `/bygge`
+
+The prototype at `tapir.d-ma.be/bygge` was **not** hand-built, which the epic and
+the first round of spike issues both got wrong. It came from these three scripts:
+
+```
+IMG_1233.mov --transcode.yaml--> IMG_1233.web.mp4   (k3s Job, h264, +faststart)
+IMG_1233.wav --whisper---------> IMG_1233.sv.srt    (interactive — the one manual step)
+IMG_1233.sv.srt --analyze_srt.py--> analys.json     (berget/mistral-medium, temperature=0)
+analys.json + video --build_page.py--> page HTML
+```
+
+The reference analysis was produced by **`berget/mistral-medium`** — a mid-tier
+cloud model, not a frontier one. That matters when judging what a local model
+has to clear: the bar is mistral-medium, and it should be re-run as the control
+arm rather than excluded.
+
+## The validator is the valuable part
+
+`analyze_srt.py` grades its own output on four checks. Two of them catch classes
+of error that timestamp- and citation-checking cannot:
+
+| Check | Catches |
+|---|---|
+| citation exact / **partial** / absent | Paraphrase presented as a quote. Three tiers, because `alternativ` citations legitimately stitch non-contiguous passages — a strict substring test fails the reference output. |
+| `TALET … FINNS INTE I CITATET` | A wrong number carried by a *verbatim* citation and a *real* timestamp. Converts Swedish number-words to digits first. It caught `45×230` where the transcript said `220`. |
+| `TACKNINGSLUCKA` | Spans of the clip no section covers. **The recall term** — without it an empty analysis scores perfectly on every other check. |
+| timestamp exists in the SRT | Fabricated seek targets. Near-solved: 74/75 on the reference, because the model copies the cue starts it was handed. |
+
+## Known defects — read before running
+
+- **`max_tokens: 6000` is too low.** The 4-minute reference analysis is ~4,700
+  output tokens, i.e. ~78% of budget. A 10-minute clip truncates for every model,
+  and truncation reads as a JSON-discipline failure if you are not counting
+  tokens. Record `finish_reason` and separate `truncated` from `malformed`.
+- **`build_page.py` hardcodes the title** (`"Jonas – genomgång av tillbyggnad"`).
+- **The schema carries fields nothing renders** — `projekt.sammanfattning`,
+  `projekt.skede`, `avsnitt.bildtid`, `avsnitt.bildmotiv`, `material[]`,
+  `oklart[]` — left over from an earlier still-frame/markdown output that
+  `build_page.py` replaced. They are paid for in output tokens on every run.
+- **Speaker attribution is inferred, not diarized.** The output attributes
+  statements by name from an SRT with no speaker labels. All four checks above
+  are blind to a misattribution.
+- **The web encode does not downscale.** The source is 720×1280; `-preset
+  veryfast -crf 24` on handheld motion is what makes it ~5 Mbps, not the
+  resolution. The lever is the preset.
+
+## Fixtures
+
+`fixtures/fake.sv.srt` + `fixtures/fake.analys.json` — a synthetic 7-cue Swedish
+construction walkthrough with planted numbers. No real people, no real project.
+It exercises the parser and all four validator checks **without a model call**,
+which is what makes it usable in a test.
+
+## Why the real artifacts are not here
+
+**This repo is public.** The prototype's transcript and analysis are a verbatim
+recording of a named person discussing a client's building project — private
+third-party content, and exactly the class of data #28 calls out as the reason
+uploaded transcripts cannot live in the shared `transcripts` table.
+
+So `IMG_1233.sv.srt`, `payload.json` and the model-comparison runs stay out of
+git here. That leaves `/bygge` without a versioned source of truth, which is a
+real gap and a decision for #28: a private repo, an encrypted blob, or accepting
+that the reference artifacts live outside version control.