fix(onboard): keep the wizard alive through provider auth failures and polish standalone install UX (#100632)

Fixes rough edges in the standalone install flow (install.sh -> openclaw onboard), found and verified by running the flow in a clean container and on a clean macOS Tahoe VM:

- Provider auth setup failures (e.g. the preselected "Anthropic Claude CLI" option on a host without a Claude CLI login) no longer kill the whole wizard. The interactive wizard notes the error and returns to the provider picker; explicit --auth-choice automation still fails fast.
- Onboarding config now persists before the channel/search/skills steps, so a crash or cancel during channel pairing no longer loses auth + gateway decisions.
- With model auth skipped, finalize no longer auto-sends the "Wake up, my friend!" message (which always failed with a provider auth error). The hatch seed is gated on usable model credentials and a "Model auth missing" note explains the next step.
- Search provider picker no longer labels non-key credentials (e.g. SearXNG base URL) as "API key required".
- install.sh no longer warns "PATH missing npm global bin dir" with manual fix steps after it already persisted the export line; it reports the PATH was updated and how to reload the current shell.
- Removed the dead interactive hooks onboarding step (setupInternalHooks); quickstart enables default hooks silently.

Verified live per fix in a clean Debian/Node 24 container and on a clean macOS 26.5 Parallels VM (wizard re-prompt, SearXNG label), plus wizard/onboard test suites and tsgo:core.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

scripts/install.sh

@@ -2487,6 +2487,20 @@ warn_shell_path_missing_dir() {
         return 0
     fi
 
+    # persist_shell_path_prepend may already have written the export line; in
+    # that case new shells are fine and the user only needs to reload this one.
+    # RC lines may spell the home dir as $HOME instead of the expanded path.
+    local dir_home_form="\$HOME${dir#"$HOME"}"
+    for rc in "$HOME/.bashrc" "$HOME/.zshrc"; do
+        if [[ -f "$rc" ]] && { grep -Fq "$dir" "$rc" || grep -Fq "$dir_home_form" "$rc"; }; then
+            echo ""
+            ui_info "PATH updated in ${rc}: added ${label} (${dir})"
+            echo "  New terminals pick this up automatically."
+            echo "  For this shell, run: source ${rc}"
+            return 0
+        fi
+    done
+
     echo ""
     ui_warn "PATH missing ${label}: ${dir}"
     echo "  This can make openclaw show as \"command not found\" in new terminals."