fix: remove all non-null assertions to fix noNonNullAssertion lint warnings

[Upd4ting]

🔗 Linked issue

N/A

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Eliminates all 20 lint/style/noNonNullAssertion Biome warnings across 8 files by replacing ! (non-null assertion) operators with safe alternatives:

Source files (5 fixes):

• components.ts — ?? "" fallback after .has() guard; early return guard for filterValue
• metadata.ts — local variable with undefined check for map iteration; null guard with error throw for schema lookup

Test files (15 fixes):

• Added getSchemaInstance() helper in utils.ts that throws on missing schema
• Replaced 8 Schema.get(...)!.instance() calls with getSchemaInstance(...) across 6 test files
• routes.test.ts — merged into single optional chain; id ?? "" fallback
• mandatory.test.ts — added if (!id) throw guards in 3 functions, removing 5 id! usages
• Cleaned up unused Schema imports in 4 files

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

Greptile Summary

This PR eliminates all 20 noNonNullAssertion Biome lint warnings across 8 files by replacing TypeScript ! non-null assertions with safe, explicit alternatives — either null-checks with early throws (which improves error observability), optional chaining with meaningful fallbacks, or the new getSchemaInstance test helper that centralises the Schema.get()!.instance() pattern.

The source-code changes in components.ts and metadata.ts are logically equivalent to the originals; no behavioral regressions were identified. The test-file changes are clean refactors.

Key highlights:

• metadata.ts setForeign now throws descriptive errors (Schema "…" not found / Unable to infer foreign table name for field "…") instead of crashing with opaque null-reference errors — a genuine improvement.
• mandatory.test.ts replaces five id! usages with explicit if (!id) throw guards, making test failures easier to diagnose.
• parseInt(val, 10) radix added in components.ts — good practice.
• Minor inconsistency: the new foreignSchema variable in Validation.Unlock is used in the .map() branch but the else branch still references field.foreign[1] directly; both are equivalent, but using the variable consistently would improve readability.

Confidence Score: 4/5

• Safe to merge — all logic in production code is preserved and the null-safety improvements are correct.
• All 20 non-null assertion replacements were traced through the code and verified to be logically equivalent to the originals. The only issue is a minor style inconsistency in Validation.Unlock where the introduced foreignSchema variable should be used consistently in both branches. No runtime regressions were identified.
• src/interfaces/data-api/beta/components.ts (minor style inconsistency in Validation.Unlock)

_{Last reviewed commit: 1521c07}

Greptile also left 1 inline comment on this PR.

[greptile-apps]

Inconsistent use of foreignSchema variable

The foreignSchema local variable was introduced to avoid the double non-null assertion field.foreign![1]! in the array branch, but the else branch still accesses field.foreign[1] directly rather than reusing the variable. For consistency, the else branch should also use foreignSchema.

Suggested change

	const foreignSchema = field.foreign[1];
	dbData[name] = Array.isArray(dbData[name])
	? dbData[name].map((entry) => fromDatabase(entry, field.foreign![1]!))
	? dbData[name].map((entry) => fromDatabase(entry, foreignSchema))
	: fromDatabase(dbData[name], field.foreign[1]);
	const foreignSchema = field.foreign[1];
	dbData[name] = Array.isArray(dbData[name])
	? dbData[name].map((entry) => fromDatabase(entry, foreignSchema))
	: fromDatabase(dbData[name], foreignSchema);

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/interfaces/data-api/beta/components.ts
Line: 491-494

Comment:
**Inconsistent use of `foreignSchema` variable**

The `foreignSchema` local variable was introduced to avoid the double non-null assertion `field.foreign![1]!` in the array branch, but the `else` branch still accesses `field.foreign[1]` directly rather than reusing the variable. For consistency, the else branch should also use `foreignSchema`.

```suggestion
        const foreignSchema = field.foreign[1];
        dbData[name] = Array.isArray(dbData[name])
          ? dbData[name].map((entry) => fromDatabase(entry, foreignSchema))
          : fromDatabase(dbData[name], foreignSchema);
```

How can I resolve this? If you propose a fix, please make it concise.