fix(build): disable minify to prevent JSC readonly property errors

[stephanschielke]

Issue for this PR

Closes #25873
Related: #25835

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Disables minify: true in packages/opencode/script/build.ts.

minify: true was added in PR #22362 (2026-04-14, tested on Windows only) to reduce binary size. Combined with effect@4.0.0-beta.58+ (introduced in v1.14.34 via PR #25524), Bun's JSC freezes mutable fold accumulator objects between iterations in compiled+minified binaries, causing Attempted to assign to readonly property on tool calls.

v1.14.33 (minify + beta.57) worked because beta.57's fold patterns create new objects each iteration. v1.14.34+ (minify + beta.59) crashes because the mutable accumulators return the same object, which JSC freezes.

Effect maintainer @mikearnaldi confirms: "This is 100% a bug in Bun's minification implementation."

Trade-off: binary size increases ~16% without minification (per PR #22362 measurements). This is acceptable until Bun fixes the underlying JSC object freezing.

Known Bun issues: oven-sh/bun#13394, oven-sh/bun#12655

Related PRs (alternative fixes):

• PR #25867: replace all mutable fold patterns with immutable runForEach
• PR #26067: revert effect to beta.57

How did you verify your code works?

1. Confirmed minify: true is the environmental trigger by testing compiled binaries with and without minification
2. bun build --compile (no minify) does NOT reproduce the error
3. bun build --compile --minify reproduces reliably on Linux x64
4. Effect maintainer confirms this is a Bun minifier bug

Screenshots / recordings

N/A (build script change, not a UI change)

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Related PRs Found

PR #25867 - fix: mutable Stream.runFold crash in compiled binaries, revert effect to beta.57
#25867

• Addresses the same root cause (mutable Stream accumulator issue) with an alternative fix approach (replace patterns with immutable runForEach)
• Mentioned in the current PR's description as an alternative fix

PR #26067 - fix(deps): revert effect to 4.0.0-beta.57 (pre-regression)
#26067

• Also addresses the same issue but via dependency revert instead of disabling minify
• Mentioned in the current PR's description as another alternative fix

These are related but not duplicates - they represent different approaches to fixing the same underlying problem. PR #26066 (current) disables minify in the build script, while #25867 and #26067 take alternative approaches.

[github-actions]

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