FN-5809: add onboarding skip-flag and env bypass handling

Ensure CLI onboarding auto-launch is bypassed cleanly via explicit flag/env controls.

- Parse and strip global `--skip-onboarding` in CLI argument preprocessing while surfacing a dedicated `skipOnboarding` signal.
- Pass the surfaced skip signal into onboarding auto-launch decisions and preserve distinct reasons (`skip-flag` vs `skip-env`).
- Tighten `FUSION_SKIP_ONBOARDING` parsing to strict truthy values only (`1`, `true`, `yes`, `on`).
- Add focused tests covering bypass reasons, truthy env parsing, global flag stripping behavior, and integration with onboarding gating.
- Add a patch changeset for @runfusion/fusion documenting the onboarding bypass behavior update.

Files changed:
 .changeset/fn-5809-skip-onboarding-bypass.md       |   9 ++
 packages/cli/src/bin.ts                            |  23 +++-
 .../__tests__/onboard-autolaunch-bypass.test.ts    | 140 +++++++++++++++++++++
 packages/cli/src/commands/onboard-autolaunch.ts    |  11 +-
 4 files changed, 173 insertions(+), 10 deletions(-)

Fusion-Task-Id: FN-5809
Fusion-Task-Lineage: fc461eab-84df-42dc-924d-9d8cc59502cd

.changeset/fn-5809-skip-onboarding-bypass.md

@@ -0,0 +1,9 @@
+---
+"@runfusion/fusion": patch
+---
+
+Refine onboarding auto-launch bypass behavior by treating `--skip-onboarding` and `FUSION_SKIP_ONBOARDING` as first-class skip paths.
+
+- Parse `FUSION_SKIP_ONBOARDING` with strict truthiness (`1`, `true`, `yes`, `on` only).
+- Return distinct auto-launch skip reasons for flag (`skip-flag`) and env (`skip-env`).
+- Strip `--skip-onboarding` as a global CLI flag so it never leaks into downstream command parsers while still informing onboarding gate decisions.