perf: improve CLI startup speed and local build speed

[devxdh]

Hello!

Since I hadn't gotten feedback on #2269 yet, I put together this Draft PR to show a working prototype of the startup speed improvements, along with a couple of quick build speed optimizations I found while working on it.

What's in this PR:

1. CLI Startup Speed (Lazy Loading)

   • Converted the top-level @asyncapi/parser import in src/apps/cli/internal/base.ts to import type and added a lazy getter/loader. Now, running basic commands doesn't parse @asyncapi/parser right away.
   • Deferred loading ValidationService, ValidationStatus, and ConversionService in validate.ts and convert.ts until run() or diagnostic handlers execute.

2. Local Build Speed (tsc --incremental)

   • Added "incremental": true and "tsBuildInfoFile": "./.tsbuildinfo" to tsconfig.json (and added .tsbuildinfo to .gitignore). This caches AST metadata so tsc doesn't re-compile all ~200 files from scratch on minor edits.

3. Skipping Example ZIP Downloads on Build

   • Updated scripts/fetch-asyncapi-example.js to check if assets/examples/examples.json already exists locally before fetching the 2MB zip from GitHub. I also added a FORCE_FETCH_EXAMPLES=true environment flag in case anyone wants to force a fresh download.

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Benchmarks (Tested on my machine)

• Local Build (npm run build): Dropped from ~19.75s down to ~6.15s (saving ~13.6 seconds per build).
• CLI Startup (time ./bin/run_bin config): Dropped from ~2.37s down to ~1.76s.
• Test Suite: All 382 tests passing cleanly.

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Question for Maintainers

Does skipping the spec example download when examples.json already exists locally look okay to you, or would you prefer a different flag/approach for fetching examples during builds?

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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