Dependabot re-proposes @types/node majors against the deliberate engines-floor pin (4th round: #481)

[pathosDev]

Problem

@types/node is pinned to the engines support floor on purpose.
ac552d5b chore(deps)!: raise runtime floors states it outright:

@types/node is pinned to the support floor (24) instead of latest so
we cannot accidentally use newer-Node APIs.

Reinforced by package.json (engines.node: ">=24.0.0") and
.github/workflows/multi-runtime.yml, which pins the Node leg to '24'
with the comment "24 deliberately — it is the engines floor we claim
to support."

Dependabot does not know this and re-proposes the major bump on every
release. So far: #334, #336, #374 (all closed), #340 (merged to 26.1.0,
then rolled back by ac552d5b), and now #481 — the fourth reopening of
the same decision. Each round costs a review and a close.

Why the pin is load-bearing

The protection is invisible to every gate we run. On #481, after syncing
bun.lock locally:

• bun run typecheck — green
• bun test — green, 3544 pass / 0 fail across 296 files

Nothing fails, because nothing can fail: the pin's whole job is to make
newer-Node APIs unrepresentable at compile time. Installing both type
majors side by side and compiling the same file against each shows what
it buys:

import { connect } from 'node:quic';
import { convertProcessSignalToExitCode } from 'node:util';

=== @types/node 24.13.3 ===
error TS2307: Cannot find module 'node:quic' or its corresponding type declarations.
error TS2305: Module '"node:util"' has no exported member 'convertProcessSignalToExitCode'.
=== @types/node 26.1.2 ===
(clean)

@types/node 26 adds whole modules that Node 24 does not have
(ffi.d.ts, quic.d.ts). Under the bump, code using them compiles and
ships, then crashes on the runtime floor we advertise.

Proposal

Add an ignore condition so the decision stops coming back:

    ignore:
      - dependency-name: "@types/node"
        update-types: ["version-update:semver-major"]

Minor and patch updates within the pinned major keep flowing. When the
engines floor is raised deliberately, the pin and this rule move
together, as they did in ac552d5b.

Acceptance sketch

• ignore rule present in .github/dependabot.yml
• chore(deps)(deps-dev): bump @types/node from 24.13.3 to 26.1.2 #481 closed with the rationale recorded
• No further @types/node major PRs

Relates to #481, #817.