Add .obvious/ agent contract from local dev onboarding

[obvious-autobuild-staging]

Obvious onboarding — .obvious/ contract

Automated onboarding run. Local dev was brought up and verified end-to-end in a sandbox; this PR adds the resulting agent contract. No application code was touched.

Files generated

• .obvious/obvious.md — top-level agent guide: stack matrix, per-app commands, Local Verification Summary, snapshot info, known limitations
• .obvious/codebase-map.md — folder-level map (depth 2, single table)
• .obvious/config.yml — repo policy auto-detected from GitHub settings (default branch master; merge/squash/rebase all enabled → squash chosen; deleteBranchOnMerge: false)
• .obvious/skills/local-dev/SKILL.md — durable local-dev record: bring-up sequence, verification checklist, gotchas

Source files scanned

All 30 tracked files across the three apps: manifests (S3-upload/package.json, mongodb-schema-importer/package.json, vue-demo/package.json), all three READMEs, entrypoints (S3-upload/index.js, mongodb-schema-importer/index.js, vue-demo/src/main.js), views/components (views/index.ejs ×2, App.vue, Welcome.vue), schema/config modules (schemas.js, configFromSchema.js), env template (env.example.js), static assets, and per-app .gitignore files. No root manifest, no root AGENTS.md, no CI configs exist.

Local dev validation result

dev_stack_healthy: true — all three demo apps run:

App	Evidence
mongodb-schema-importer	mongod 4.4.29 up on :28015 (npm run mongod); GET /populate-defaults → 200 "Inserted 4 Robots"; GET / → 200 with DB-derived importer fields (name, nick, helmet, color, id) plus Mongoose Robot schema config (6 fields)
S3-upload	npm start with dummy AWS env credentials → GET / 200, page renders a presigned S3 putObject URL
vue-demo	yarn serve (needs NODE_OPTIONS=--openssl-legacy-provider on Node ≥ 17) → compiled successfully, HTTP 200 on :8080, HMR active; yarn lint → no lint errors

Playwright Chromium screenshots captured for all three apps; console inspected (apps boot cleanly; the Flatfile widget iframe is refused without a real license, as expected). Full details in .obvious/obvious.md → "Local Verification Summary".

Notable fix during bring-up: MongoDB 8.x rejects this repo's pinned mongodb@~3.0.8 driver (legacy OP_QUERY wire protocol) — the app crashes on /populate-defaults. mongod 4.4.29 is installed in the sandbox instead and the constraint is documented in the contract.

Sandbox snapshot

• Snapshot ID: gap0pvit10wten6lqhs1:default (sandbox i517zqa9z31yfh4v3rhj1)
• Captured: 2026-08-24T21:29:58.777Z
• State: deps installed for all three apps; gitignored local configs created (mongodb-schema-importer/.env.js, vue-demo/env.js); mongod 4.4.29 running with seeded robots collection; mongodb-schema-importer live on :9000 and vue-demo on :8080; git tree clean.

Blockers

None. Notes (not blockers): the in-browser Flatfile importer widget requires a real Flatfile license key (external SaaS) and real S3 uploads require real AWS credentials — all server-side and page-render flows were verified with safe placeholder values.

Explicit omissions

• None of the contract files were omitted — the repo was not empty, so all four files (obvious.md, codebase-map.md, config.yml, skills/local-dev/SKILL.md) are included.
• No .obvious/tools/, no .obvious/system-prompt.md, no root AGENTS.md created or modified; no .obvious-install/ staged.
• The only TODO(confirm) in the contract: obtaining a real Flatfile license key to exercise the full in-browser import flow.