feat: add iconv runtime wrapper

[Mistat]

Summary

• Add @tailor-platform/sdk/iconv — a typed wrapper around the platform's tailor.iconv runtime API for character encoding conversion (Shift_JIS, EUC-JP, IBM EBCDIC, etc.)
• Add setupIconvMock test helper to @tailor-platform/sdk/test
• Add docs/iconv.md referencing the official Character Encoding Conversion page, plus README and SKILL.md links

Closes a gap previously identified in the SDK: the platform exposes tailor.iconv globally via @tailor-platform/function-types, but the SDK had no first-class typed export for it. This PR adds one in the same style as the existing @tailor-platform/sdk/kysely runtime utility.

API surface

import { convert, convertBuffer, decode, encode, encodings, Iconv } from "@tailor-platform/sdk/iconv";

const sjis = convert("こんにちは", "UTF-8", "Shift_JIS"); // Uint8Array
const utf8 = convert(sjisBuffer, "Shift_JIS", "UTF-8");   // string

const conv = new Iconv("Shift_JIS", "UTF-8");
conv.convert(buffer);

Return type narrows to string when toEncoding is "UTF-8" / "UTF8", otherwise Uint8Array — matches the platform's declared types.

Test plan

• pnpm vitest run --project=unit src/iconv — 11/11 passing (incl. type-level checks for return-type narrowing)
• pnpm build — dist/iconv/{index.mjs, index.d.mts} generated
• pnpm publint --strict — All good
• pnpm knip — clean
• lefthook pre-commit (build / lint / typecheck:go / knip / format) — all pass
• Verify import { convert } from "@tailor-platform/sdk/iconv" resolves cleanly in a downstream project after publish

🤖 Generated with Claude Code

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[changeset-bot]

🦋 Changeset detected

Latest commit: d5427a9

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@tailor-platform/sdk	Minor
@tailor-platform/create-sdk	Minor

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[github-actions]

⚡ pkg.pr.new

@tailor-platform/sdk

pnpm add https://pkg.pr.new/@tailor-platform/sdk@d5427a9

pnpm dlx https://pkg.pr.new/@tailor-platform/sdk@d5427a9 --help

@tailor-platform/create-sdk

pnpm add https://pkg.pr.new/@tailor-platform/create-sdk@d5427a9

pnpm dlx https://pkg.pr.new/@tailor-platform/create-sdk@d5427a9 my-app

commit: d5427a9

[claude]

📖 Docs Consistency Check

⚠️ Inconsistencies Found

File	Issue	Suggested Fix
packages/sdk/docs/testing.md	Missing documentation for setupIconvMock test helper	Add a section documenting setupIconvMock similar to how setupWaitPointMock is documented

Details

Missing setupIconvMock in testing.md

The PR adds a new test helper setupIconvMock() that is:

• Exported from @tailor-platform/sdk/test (packages/sdk/src/utils/test/index.ts:12)
• Documented in packages/sdk/docs/iconv.md (lines 138-174)
• Following the same pattern as other mock helpers

However, packages/sdk/docs/testing.md documents other mock helpers like:

• setupWaitPointMock - documented at lines 176 and 296
• setupWorkflowMock - referenced in workflow testing sections
• Database mocking patterns - documented in the "Mock TailorDB Client" section

For consistency, setupIconvMock should be documented in testing.md. This would help users discover the helper when they need to test code that uses @tailor-platform/sdk/iconv.

Suggested location: Add a new subsection under "Unit Tests" (after line 215) titled "Testing Code that Uses iconv" with:

• Basic example of using setupIconvMock()
• How to customize behavior via onConvert, onDecode, onEncode
• Cleanup pattern (deleting TailorGlobal.tailor in afterEach)
• Reference to the full documentation in iconv.md

✅ Verified Consistent

• API documentation (iconv.md): All exported functions (convert, convertBuffer, decode, encode, encodings, Iconv) are correctly documented with accurate signatures and return types
• README.md: Correctly links to iconv.md under "Runtime Utilities" section (line 88)
• Package exports: ./iconv export in package.json (lines 47-51) matches the implementation
• Test helper export: setupIconvMock is properly exported from @tailor-platform/sdk/test
• SKILL.md: References iconv docs (line 20 and 34)
• Changeset: Accurately describes the changes
• iconv.md Testing section: Provides comprehensive examples of using setupIconvMock

Recommended Actions

1. Add a subsection in packages/sdk/docs/testing.md documenting setupIconvMock to maintain consistency with other mock helpers
2. Consider cross-referencing from testing.md to iconv.md's Testing section for the full example

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.

[github-actions]

Code Metrics Report (packages/sdk)

	main (25eda96)	#1069 (38f3ef2)	+/-
Coverage	59.4%	59.5%	+0.1%
Code to Test Ratio	1:0.4	1:0.4	+0.0

Details

  |                    | main (25eda96) | #1069 (38f3ef2) |  +/-  |
  |--------------------|----------------|-----------------|-------|
+ | Coverage           |          59.4% |           59.5% | +0.1% |
  |   Files            |            351 |             352 |    +1 |
  |   Lines            |          11938 |           11969 |   +31 |
+ |   Covered          |           7092 |            7123 |   +31 |
+ | Code to Test Ratio |          1:0.4 |           1:0.4 |  +0.0 |
  |   Code             |          78060 |           78270 |  +210 |
+ |   Test             |          31657 |           31750 |   +93 |

Code coverage of files in pull request scope (73.9% → 82.0%)

Files	Coverage	+/-	Status
packages/sdk/src/iconv/index.ts	100.0%	+100.0%	added
packages/sdk/src/utils/test/index.ts	100.0%	0.0%	modified
packages/sdk/src/utils/test/mock.ts	72.7%	+15.5%	modified

SDK Configure Bundle Size

	main (25eda96)	#1069 (38f3ef2)	+/-
configure-index-size	17.17KB	17.17KB	0KB
dependency-chunks-size	33.25KB	33.25KB	0KB
total-bundle-size	50.42KB	50.42KB	0KB

Runtime Performance

	main (25eda96)	#1069 (38f3ef2)	+/-
Generate Median	2,571ms	2,578ms	7ms
Generate Max	2,679ms	2,612ms	-67ms
Apply Build Median	2,658ms	2,628ms	-30ms
Apply Build Max	2,700ms	2,662ms	-38ms

Type Performance (instantiations)

	main (25eda96)	#1069 (38f3ef2)	+/-
tailordb-basic	35,130	35,130	0
tailordb-optional	3,841	3,841	0
tailordb-relation	7,428	7,428	0
tailordb-validate	2,566	2,566	0
tailordb-hooks	5,767	5,767	0
tailordb-object	12,136	12,136	0
tailordb-enum	2,462	2,462	0
resolver-basic	9,424	9,424	0
resolver-nested	26,111	26,111	0
resolver-array	18,187	18,187	0
executor-schedule	4,234	4,234	0
executor-webhook	873	873	0
executor-record	8,166	8,166	0
executor-resolver	4,369	4,369	0
executor-operation-function	869	869	0
executor-operation-gql	869	869	0
executor-operation-webhook	888	888	0
executor-operation-workflow	1,714	1,714	0

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Reported by octocov

[toiroakr]

I plan to handle this in #1131, including the changes from this PR.