Upgrade the Pi SDK and refresh its model catalog

[amadad]

Summary

• Move BB's Pi bridge and server inference helpers from @mariozechner/pi-* 0.70.5 to @earendil-works/pi-* 0.82.0.
• Use one shared ModelRuntime for model resolution, authentication, session creation, and catalog refresh. The picker now reflects each model's supported reasoning levels, including max.
• Keep retryable Pi failures inside the active BB turn by honoring agent_end.willRetry.
• Bundle Pi's jiti/static dependency and register Pi's static OAuth loaders so the standalone bridge can authenticate without filesystem-only dynamic imports.
• Raise the supported Node.js floor to 22.19 and remove the Node 20 compatibility job and shim.

Why

BB was pinned to Pi 0.70.5 under the retired package namespace. Its static model APIs could not expose models added through Pi's current catalog. The new runtime API keeps session and catalog behavior under one owner while preserving BB's existing bridge protocol.

The server pins @opentelemetry/api to the workspace version so Pi AI and Drizzle resolve one shared type identity.

Compatibility

• Supported Node.js versions are 22.19, 24, and 26.
• Pi remains an SDK bundled with BB. This does not switch the provider to an independently installed Pi CLI.
• The server-to-daemon wire contract is unchanged, so this does not require a host daemon protocol bump.

Verification

• pnpm install --frozen-lockfile
• pnpm exec turbo run build typecheck lint --concurrency=1 --force (68 tasks)
• Agent runtime: 41 files, 803 tests
• Server: 148 files, 1,255 tests
• bb-app: 2 files, 47 tests
• pnpm exec turbo run smoke:tarball --filter=bb-app --force
• Bundled OAuth probe: stored openai-codex credentials resolve inside the single-file bridge
• Packaged Pi bridge model discovery: 96 models, including six GPT-5.6 variants; eight models advertise max

[amadad]

Live testing exposed one bundle-only OAuth failure: Pi’s lazy OAuth loader resolved ./openai-codex.js relative to the generated single-file bridge. Commit 5e157ef7 registers Pi’s static OAuth loaders at bridge startup.

Proof: the regression test failed before the change and passes after it; all 803 agent-runtime tests pass; the tarball smoke passes; and a bundled openai-codex/gpt-5.6-luna turn completed successfully with stored OAuth credentials.

[amadad]

Rebased onto main and added one commit.

fix: refresh the Pi model catalog once per bridge process — as originally filed this PR shipped a regression it introduced. listPiBridgeModels called modelRuntime.refresh({ allowNetwork: true }) on every invocation, so each model list fanned out one network request per configured provider to pi.dev. It runs on every picker render and on thread-detail bootstrap with nothing cached between the browser and the bridge, so a stalled provider endpoint burned the full 5s abort budget. Measured per call: ~8-9ms warm, 274-375ms cold, 5,010ms on 2 of 6 cold runs. The refresh is now attempted at most once per bridge process; later calls resolve from the persisted store plus the bundled static catalog and return the same model set. It also stops memoizing a rejected ModelRuntime.create(), which previously cached a single transient failure for the life of the process and left every model list and session start broken until the bridge restarted.

Two things that may make the Node floor less of a decision than it looks:

• @mariozechner/pi-ai is deprecated on npm — npm view @mariozechner/pi-ai@0.73.1 deprecated returns "please use @earendil-works/pi-ai instead going forward". The current pin is on a retired namespace, and the newer releases under it carry the same notice.
• Node 20 was already best-effort here before this PR: docs/platform-support.md said "Node.js 20 is best-effort only because it is end-of-life upstream", packages/bb-app/README.md says "Node 20.19.x is best-effort only", and the Node 20 CI job already ran with continue-on-error: true. This PR removes a non-blocking job and a support tier the docs had already marked EOL.

Happy to split this differently if you'd rather review the namespace migration and the runtime unification separately — say the word and I'll restructure.

[amadad]

CI caught a real defect in the previous push — fixed and force-pushed.

The Node 20 cleanup had removed the globalThis.navigator shim in packages/plugin-build/scripts/generate-runtime-export-manifest.mjs, which broke runtime-export-manifest.test.ts > runs when Node does not provide a global Navigator. That was wrong on my part: the test deletes globalThis.navigator explicitly to prove export introspection survives without it, so the shim guards a scenario the supported-Node floor has no bearing on — @pierre/diffs reads navigator.userAgent during module initialization regardless of Node version. The shim is restored verbatim, and this PR no longer touches packages/plugin-build at all.

Verified locally on the pushed commit, replicating the CI shard:

• pnpm exec turbo run test --filter='!@bb/server' --filter='!@bb/app' --filter='!@bb/integration-tests' — 48/48 packages passing, including @bb/plugin-build 6/6
• One further exclusion: @bb/host-daemon's command-dispatch.test.ts > reuses a busy runtime when thread.start carries a changed skill catalog fails on my machine with "Codex 0.101.0 is too old for this bb version". It reproduces identically on a clean origin/main checkout, so it is a local Codex version artifact and unrelated to this branch.