[MEDIUM] BashTool depth: 11 validation modules missing

[tuterx]

Real CC BashTool has 11 sub-modules (readOnlyValidation, destructiveCommandWarning, modeValidation, sedValidation, pathValidation, commandSemantics, bashPermissions, bashSecurity, shouldUseSandbox, sedEditParser). Claw-code has only bash execution.

Fix: Merge bash_validation branch (1004 LOC) to main. Implement remaining modules.