CL-6589: run only affected packages, cache prettier and eslint

[TheGreatAxios]

bun run check runs all 109 workspace packages regardless of what moved, and test is in SEQUENTIAL_SCRIPTS — so 106 test jobs run one at a time on an 8-core machine. A one-line edit pays for the whole repo. That is the multi-minute local gate.

What this adds

WORKBENCH_CHECK_SINCE=<ref> narrows the job list to the packages a change touches plus everything that transitively depends on them. Measured against the real 109-package graph:

edited package	packages checked	reduction
slug	6 / 109	18x
folded-runs	31 / 109	3.5x
inference-catalog	32 / 109	3.4x

It helps test most, precisely because that phase is sequential.

Opt-in. Unset, every package runs, so CI and a bare bun run check keep their current meaning. Local use:

WORKBENCH_CHECK_SINCE=origin/main bun run typecheck

Correctness over speed. A change to a root manifest, bun.lock, the shared tsconfig, the eslint config, scripts/, or .github/ has a blast radius no dependency edge records, so those force a full run. Dependents are walked to a fixed point, so a dependency cycle terminates instead of recursing. A filtered gate that misses a break is worse than a slow one.

Also: pins hono

Two resolved copies (4.13.2 via a transitive GitHub dep, 4.13.3 everywhere else) produce structurally identical but nominally distinct Hono types. The mismatch surfaces as an unreadable multi-screen TS2345 in whichever package bridges them.

What this deliberately does not change

test stays sequential. The comment in sequential-scripts.ts says several suites bind sockets and share Postgres, and making them concurrent is a real piece of work — not something to slip into a speedup PR. Narrowing the job list gets most of the win without that risk.

Note on the two typecheck errors seen locally

They were stale install state, not code: two @corbits/memory trees and two hono trees left behind by earlier installs, plus a tsconfig.tsbuildinfo caching a path that no longer existed. Verified clean in a fresh-install worktree. The hono pin prevents the duplicate recurring; the stale-tree pruning is a local rm -rf node_modules && bun install.

[TheGreatAxios]

Rebased onto latest main and added lint caching.

Measured on this repo

step	before	after (warm)
prettier	19.5s	7.1s
eslint	108s	2.4s
bun run lint total	~127s	4.3s

eslint was by far the biggest single cost in the gate and re-linted every file on every run. Neither tool's result changes for a file that has not changed, so both now cache on content.

Cold cost is unchanged, so CI (fresh checkout, no cache) is unaffected — this buys back the local edit-check loop. .eslintcache is gitignored.

Combined with the affected-package filter, a local check on a leaf package now touches 6 of 109 packages and skips ~123s of redundant linting.