[Platform] Integration v2

Description

The pitch.

## Purpose

**Rebuild post-schema-recon + post-live-judge.** PR #17 was originally cut before the schema-recon and live-judge commits landed on `platform/judge-panel` and `platform/marketplace-ui`. This is a clean rebuild on top of the latest HEAD of each source branch so reviewers can see the integrated state of all five platform tracks as it would look on `main`.

Integration is built from `origin/main` and merges in PRs #12, #13, #14, #15, #16 via `--no-ff` merge commits (no rebase, no history rewrite), with one optional README-dedupe polish commit on top.

## Source branch HEADs (rebuild input)

| Branch | HEAD | Latest commit |
| --- | --- | --- |
| `origin/platform/ci-hygiene`       | `0de32f2` | Add CI hygiene tooling: Makefile, pre-commit, feedback bot, Definition of Done |
| `origin/platform/open-problems`    | `228a697` | docs(judging): align with canonical rubric and judge panel behavior |
| `origin/platform/judge-panel`      | `d1150b9` | test(judge): update gpt-5.5 temperature assertion + add gpt-4o coverage (includes schema-recon + OpenAI provider + live judge scores + temperature fix) |
| `origin/platform/research-harness` | `a530450` | Add research harness for A/B hackathon experiments |
| `origin/platform/marketplace-ui`   | `02d49f9` | fix(marketplace): consume judge panel's real scores.json shape (schema-recon adapter rewrite) |

**New integration HEAD:** `a64bc29` (on `platform/integration`, force-pushed).

## Merge log

Merged in this order, each as a `--no-ff` merge commit:

1. `origin/platform/ci-hygiene` (PR #12) — clean auto-merge.
2. `origin/platform/open-problems` (PR #13) — clean auto-merge (README appended).
3. `origin/platform/judge-panel` (PR #14) — clean auto-merge (now includes the live-judge scoreboard + OpenAI provider + temperature gating + gpt-4o test coverage).
4. `origin/platform/research-harness` (PR #15) — **1 conflict** in `pyproject.toml`, resolved by union.
5. `origin/platform/marketplace-ui` (PR #16) — **1 conflict** in `pyproject.toml`, resolved by union (now consumes the real `scores.json` shape post schema-recon).

Plus one post-merge polish commit (`a64bc29`) to dedupe a duplicate `## Hackathon` header in README.md.

## Conflicts hit and how each was resolved

### `pyproject.toml` (merging `platform/research-harness`) — UNION

`[tool.pytest.ini_options]` and `[project.optional-dependencies]` conflicted. Both sides additive, resolved by union per the integration brief:

- `testpaths = ["packages", "scripts"]` — `scripts` is a superset of `scripts/harness/dry_run`, collects both judge and harness tests.
- `addopts = ["--import-mode=importlib", "-m", "not live"]` — kept judge-panel's `not live` filter so CI doesn't hit the network.
- `pythonpath = ["."]` — from research-harness.
- `markers = ["live: ..."]` — from judge-panel.
- `[project.optional-dependencies]` now contains both `judge` (anthropic + openai) and `harness` (matplotlib + PyYAML) extras.

### `pyproject.toml` (merging `platform/marketplace-ui`) — UNION

`[tool.pyright].extraPaths` conflicted. HEAD had `"."` (from research-harness), incoming had `"packages/nest-marketplace"`. Both kept:

```
"packages/nest-plugins-reference",
"packages/nest-marketplace",
".",
```

### README.md duplicate `## Hackathon` header — UNION + dedupe (post-merge polish)

Both `platform/open-problems` and `platform/judge-panel` appended `## Hackathon` sections to README.md in different regions; git auto-merged both without conflict, leaving two identically-titled H2s. Per the brief's README rule (deduplicate literal overlap), the second section was renamed to `## Scoreboard`, the overview was lightly augmented to mention the scoreboard, and the TOC was updated to match.

This is the only editorial change on the integration branch; everything else is a true merge commit.

**Total conflicts resolved: 2 file-level conflicts (both in `pyproject.toml`), plus 1 README dedupe in the polish commit.**

## CI evidence

`make ci-local` is green on the head

…