v0.3.1 — security fix: BOM-prefixed configs no longer vanish from reports

Upgrade recommended for anyone using --strict or --diff as a drift alarm.

Fixed: configs starting with a byte-order mark were silently skipped

A JSON config whose first bytes were a UTF-8 byte-order mark (BOM) failed to
parse. Notepad, older Visual Studio and PowerShell 5.1 write one by default,
so hand-edited configs on Windows were affected.

• MCP configs in project and host locations (Cursor, Claude Desktop,
  Windsurf, VS Code and others) showed a single "unparseable config" line
  with no exposures. Servers that could execute code or held credentials were
  not reported, and --strict exited 0.
• Worse: the global Claude Code config, Claude Code settings (hooks and the
  API-key helper), Cursor and Gemini CLI hook files, and the Claude Code
  plugin list dropped parse errors entirely. A BOM made their servers and
  hooks disappear without any trace.
• As a result the drift alarm could be bypassed: a new hook added in a
  BOM-prefixed settings file produced "no drift — this machine matches the
  baseline" and exit 0.

The BOM is now stripped when a file is read, so these configs parse normally.
Separately, every reader that used to drop a parse error now reports the file
as an "unparseable config" finding instead of skipping it.

Fixed: parse errors could copy part of a credential into reports

When a config was malformed right next to a credential without a recognizable
shape, the parser's error message could carry up to about ten characters of
the value into the --json and --html reports (not the terminal). Parse
errors are now labeled by line and column only, with no file content.

Changed: unparseable configs are shape-scanned

A config that exists but cannot be parsed is now scanned for credential
shapes like any partially parseable format (HOLDS-SECRETS when found), and
the finding says when the file appears to declare MCP servers or hooks. The
README's limitations section is corrected to match.

Credit

The BOM issue was reported privately, with an exact reproduction, by an
independent researcher who runs verification passes on security tooling.
Thank you. The error-message leak and the wider silent-drop cases were found
while fixing it.

Tests added for all of the above. Read-only, no telemetry, secrets by shape
only — unchanged, and now enforced on the parse-error path too.