fix: preserve literal dollar sequences in replace-all edits

[hetaoBackend]

Change

Fixes #155. Bulk edits now insert replacement text literally: $$, $&, dollar-backtick, and dollar-apostrophe remain unchanged instead of collapsing dollars, reinserting the match, or duplicating surrounding file content.

Use a replacement callback in the shared replace-all helper. Add 12 regression cases covering helper output and occurrence counts, actual LocalEditTool file writes with multiple matches, and single-edit controls. Register the test in the capability suite and regenerate the public source inventory.

Validation

• Before the fix: all eight bulk-edit assertions failed; all four single-edit controls passed.
• After the fix: all 12 focused regression cases passed.
• git diff --check: passed. pnpm verify on clean commit 9a35236fdc2ca1944c8e3b6eddbd7a50fee8ac22: all 14 full-profile gates passed on macOS arm64, Node.js 26.4.0 (including source export, typecheck, build, capability regressions, smoke, offline BYOK, policy and sandbox).
• NOT RUN: live-model or published-package acceptance; local verification does not establish Linux/Windows acceptance.

Publication and contribution checks

• Changes are contributed under the existing applicable licenses; existing notices are preserved. No third-party code is imported.
• No credentials, account data, real user content, internal source history or private review material is included. Tests use synthetic temporary files.
• The added test was reviewed before regenerating release/public-source.json and is declared in test/vitest-suites.json.
• No documentation or capability changes are required; this restores the existing literal edit contract. Offline results are not described as live-service acceptance.

Maintainer handoff

No publication scope or license changes. Shared-source port: pending.

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