icp-cli: agents use 'candid:' instead of 'didFile:' in the bindgen Vite plugin config

Surfaced while running evals for the #364 PR. Pre-existing — not introduced by that PR (verified below), so filing separately rather than widening its scope.

Symptom

evaluations/icp-cli.json case 15 ("Full-stack Motoko config artifacts") fails one behavior with the skill loaded:

❌ Uses @icp-sdk/bindgen (>= 0.4.0) Vite plugin with a didFile path pointing to the committed .did file
   → The bindgen block uses a 'candid' key instead of the required 'didFile' key,
     and no version is specified for @icp-sdk/bindgen.

The model writes the Vite plugin as icpBindgen({ candid: "...", outDir: "..." }) instead of didFile:. That config is silently wrong — bindgen ignores the unknown key and has no .did path.

Confirmed pre-existing

Case 15 was re-run against the unmodified skill content (whole change set stashed):

BEFORE:  ❌ ... configures the path via a 'candid' key instead of the expected 'didFile' field
AFTER:   ❌ ... uses a 'candid' key instead of the required 'didFile' key

Identical failure, identical reason, 5/6 both ways. The only line the #364 PR touches on that case is the version number inside the expectation string.

Root cause: two different keys for the same concept

The skill uses two key names for "path to the .did file", and the wrong one dominates by weight:

An agent reading SKILL.md — the entry point — sees candid: presented four times as the key for the .did path and didFile essentially never. binding-generation.md:91 then compounds it by discussing candid: in the same paragraph as bindgen:

…commit it to the repo, and specify candid: in the recipe config. If candid is omitted, the recipe auto-generates the .did…

Nothing anywhere states that these are two distinct keys in two distinct files.

Suggested fix

Make the distinction explicit rather than implicit — one sentence in binding-generation.md next to the Vite example, and a clause in SKILL.md pitfall 12:

The bindgen Vite plugin key is didFile, not candid. candid: is an icp.yaml recipe.configuration key that tells the recipe where the .did is; didFile: tells the binding generator. They point at the same file from two different config files, and bindgen silently ignores an unknown candid key.

Then re-run node scripts/evaluate-skills.js icp-cli --eval 15 — it should go 6/6.

Start with skills/icp-cli/SKILL.md, especially pitfall 12, and skills/icp-cli/binding-generation.md beside the Vite example. Make the distinction between candid in icp.yaml recipe.configuration and didFile in icpBindgen explicit, then run node scripts/evaluate-skills.js icp-cli --eval 15; done is a 6/6 result.