Shell snapshot filters _-prefixed functions, breaking dependent exported functions (GVM _encode/_decode)

Description

Claude Code's shell snapshot mechanism filters out shell functions whose names start with _. This causes breakage when exported functions (which are captured in the snapshot) internally call _-prefixed helpers (which are not captured).

Steps to Reproduce

1. Install GVM (Go Version Manager)
2. Source GVM in ~/.zshrc: [[ -s "$HOME/.gvm/scripts/gvm" ]] && source "$HOME/.gvm/scripts/gvm"
3. Open Claude Code and run any bash command that triggers a cd call

What Happens

GVM overrides the cd shell function. This override calls setValueForKeyFakeAssocArray (captured in snapshot), which in turn calls _encode/_decode (defined in ~/.gvm/scripts/function/_bash_pseudo_hash, filtered from snapshot).

Every bash command that causes a directory change produces:

setValueForKeyFakeAssocArray:27: command not found: _encode
valueForKeyFakeAssocArray:28: command not found: _decode

Root Cause

In ~/.claude/shell-snapshots/snapshot-zsh-*.sh, functions like setValueForKeyFakeAssocArray and valueForKeyFakeAssocArray are present (they don't start with _), but _encode and _decode — which they depend on — are absent because the snapshot capture filters all _-prefixed function names.

The snapshot files are consistently 6997 lines and do not contain a single ^_[a-z] function definition, confirming the filter is applied broadly.

Expected Behavior

The snapshot should either:

• Follow function call dependencies and include _-prefixed functions that are called by captured functions, or
• Not filter _-prefixed functions from the snapshot at all (they are legitimate shell functions, not internal shell builtins)

Impact

• Stderr noise on every bash command involving cd
• GVM's Go version auto-switching fails silently in Claude Code's bash context
• Affects any user with shell setups where public functions depend on _-prefixed helpers (GVM, some zsh plugins, custom scripts)

Environment

• macOS Darwin 25.4.0 (arm64)
• Shell: zsh
• GVM installed at ~/.gvm
• Claude Code CLI