test: add integration wiring and input parsing tests for enterprise features

Add three test files covering the two highest-priority gaps in PR #777:

1. src/index-enterprise-features.test.ts (21 tests) - Integration wiring
   tests for index.ts that verify conditional gating of all enterprise
   services (GitHooks, LocalCache, ChildWorkspace, SubmoduleProfile,
   LfsAgent). Tests that disabled features (default) are never invoked,
   enabled features call the correct service methods, and the order of
   operations is correct (restore before build, save after build).
   Also tests non-local provider strategy skips all enterprise features.

2. src/model/enterprise-inputs.test.ts (103 tests) - Input/BuildParameters
   wiring tests for all 20 new enterprise properties. Covers defaults,
   explicit values, and boolean string parsing edge cases (the #1 source
   of bugs: 'false' as truthy, 'TRUE' case sensitivity, '1', 'yes').
   Verifies BuildParameters.create() correctly maps all Input getters.

3. src/model/orchestrator/services/submodule/submodule-profile-service.test.ts
   (5 new tests) - Command construction safety tests for execute(),
   documenting how paths, branches, and tokens are passed into git
   commands and verifying the expected command strings.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: frostebite