feat(init): add bounded stateless file reads

[betegon]

Summary

This is the CLI half of bounded, stateless read-files support for sentry init.

• add an opt-in V2 response with one structured content/error result per requested path
• accept startLine, maxLines, and maxBytes in the request, but return no cursor, file version, or continuation state
• return complete lines only; callers can issue another independent range read or use grep when they need different evidence
• cap all returned content across the request at 40 KB and bound deep line lookup at 4 MiB
• read from an open descriptor with containment, regular-file, identity, stability, UTF-8, binary, symlink-target, and sensitive-path checks
• preserve the existing V1 response shape for older API deployments

Compatibility

The protocol is negotiated per request. An older API never asks for V2, so this CLI keeps returning the V1 shape. A newer API accepts V1 from older CLI releases and treats ambiguous truncation conservatively.

Companion API PR: https://github.com/getsentry/cli-init-api/pull/234

Test plan

• pnpm --filter sentry typecheck
• focused filesystem suite: 17 tests
• focused Biome check for the three changed files
• pnpm test:unit: changed tests pass; the full run retains two unrelated completion-simulation failures from the local shell environment
• git diff --check

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Project	Deployment	Actions	Updated (UTC)
cli	Ready	Preview	Aug 18, 2026 1:52pm

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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