Hermes Agent target emits broken YAML in `platform_toolsets` block via `codegraph install`

[pty819]

Bug

Running codegraph install --target hermes (or interactive install selecting Hermes Agent) produces broken YAML in ~/.hermes/config.yaml. The platform_toolsets.cli section has - hermes-cli at the wrong indentation level, causing yaml.safe_load to raise a ParserError.

Broken output

platform_toolsets:
  cli:
    - mcp-codegraph
  - hermes-cli    # ← wrong: at cli: level instead of inside

Correct output (from --print-config)

platform_toolsets:
  cli:
    - hermes-cli
    - mcp-codegraph

Note that --print-config produces correct YAML, but the actual writeHermesConfig() → upsertCodeGraphToolset() code path does not.

Error

yaml.parser.ParserError: while parsing a block mapping
  in "config.yaml", line 547, column 3
expected <block end>, but found 

Affected code

File: src/installer/targets/hermes.ts → compiled lib/dist/installer/targets/hermes.js

Function: upsertCodeGraphToolset (lines 259-281)

Three code paths:

1. !parent (no platform_toolsets: block) — appends correct YAML at EOF. ✅
2. !cli (block exists but no cli: child) — splices correct YAML. ✅
3. cli exists — either returns unchanged or appends mcp-codegraph at cli.end. ❓

The broken output (- hermes-cli outside cli:) does not match any of these insertion patterns, suggesting a subtle edge case in childRange end-boundary detection (line 178, regex /^\s\S/ on line 194) or topLevelRange (line 162) when there are other sibling children under platform_toolsets.

Environment

• codegraph version: 0.9.5
• Hermes Agent: latest
• config location: ~/.hermes/config.yaml (global)
• OS: Linux (arm64)

Additional context

The --print-config hermes output is correct — the bug manifests only in the actual file-writing path. This was discovered on a fresh install where platform_toolsets did not exist in the config beforehand (so the !parent branch was taken), yet the resulting YAML had the malformed structure shown above.

[colbymchenry]

Duplicate of #456 — fixed by #461, which merged ~4 hours after v0.9.5 went out so it didn't make that release. The fix (listChildBlock helper in src/installer/targets/hermes.ts) recognizes PyYAML's same-indent list style (cli: and - hermes-cli both at column 2) so the patcher no longer mistakes the first list item for a sibling key. Ships in the next release; CHANGELOG entry is already staged under [Unreleased] > Fixed. Thanks for the detailed report — the affected-code analysis pointing at upsertCodeGraphToolset matched the fix exactly.