feat(push): warn on npm --omit=dev + tsc build script (typescript compilation trap)

[DaveHanns]

Summary

Add a pre-upload sanity check in apify push that warns (never blocks) when
the project's Dockerfile drops devDependencies before running a tsc-based
build. This is one of the most common "worked locally, fails on the platform"
traps for TypeScript Actors, and the platform build error (tsc: not found)
gives no hint that the fix is on the Dockerfile side.

Companion PR to apify/apify-docs #2716 (documents the same trap). Finding
F30-companion from the agentic-actor-development eval sweep.

What changes

• src/commands/actors/push.ts
  • New exported helper detectOmitDevTscTrap(cwd) — pure function, returns
    a warning message or null. Handles both .actor/Dockerfile and
    ./Dockerfile, folds backslash line-continuations, matches both
    --omit=dev and --production, and refuses to fire on tsc-alias,
    tsdown, or when typescript is duplicated into dependencies.
  • The run() handler calls it right after the "Deploying Actor" log line
    and emits the message through the existing yellow warning() output
    helper (goes to stderr). Push proceeds either way.
• test/local/commands/push.test.ts
  • Nine unit cases covering positive matches and the four falsy-signal
    guards (typescript in both, no --omit, non-tsc build, missing
    Dockerfile / malformed package.json).

Design notes:

• Warning only, never a validation error — the platform's Docker build is
  still authoritative, and we don't want a heuristic to block anyone.
• All file access is guarded with existsSync + try/catch so a missing or
  unreadable Dockerfile / package.json silently no-ops.
• The tsc regex is a word-boundary-ish match (^|[\s&|;])tsc($|[\s&|;])
  so we don't false-positive on tsc-alias, tsconfig-paths, tsdown, etc.

Test plan

• oxlint --type-aware clean on push.ts and push.test.ts
• tsc --noEmit -p . clean
• Standalone repro of the 9 test cases (positive/negative matrix) all pass
• CI test suite green (delegating to reviewer / GitHub Actions)
• Manual: run apify push in a project with a single-stage
  --omit=dev Dockerfile + tsc build script and confirm the yellow
  warning appears before the upload phase
• Manual: run apify push in a well-configured multi-stage project and
  confirm no warning fires

Cross-references

• Finding F30-companion (agentic-actor-development eval sweep)
• Docs companion: apify/apify-docs #2716