mios.toml: NEW [messages.elevation] + [messages.pass2_exit]

Two more SSOT sections for previously-hardcoded operator-facing
prose:

[messages.elevation] -- the 3-line UAC handoff banner shown
immediately before the Pass-1 -> Pass-2 elevation prompt.
Operator sees these every irm|iex run as a non-admin first
launch.

  admin_required   -- "MiOS bootstrap requires admin..."
  uac_trigger_line -- "Triggering UAC -- accept to continue..."
  uac_trigger_hint -- "in the elevated window, single prompt..."

[messages.pass2_exit] -- 5 strings emitted by the Pass-2 inner
heredoc when the bootstrap completes / fails / asks the operator
to close the elevated window:

  exited_code_prefix -- "[!] Bootstrap exited with code N"
  failure_detail     -- "Output above is the failure detail..."
  build_log_hint     -- "build-mios.ps1's own log only kicks in
                       on Pass-2 success."
  fetch_run_failed   -- "[!] Bootstrap fetch/run failed: <err>"
  press_enter_close  -- "Press Enter to close this elevated
                       bootstrap window..."

Companion mios-bootstrap commit (c434302) wires both sections
into the resolvers:
  * Get-MiOS.ps1 Pass-1 banner reads via Get-MiosTomlValue at
    runtime (admin elevation runs in the live process).
  * Get-MiOS.ps1 builds the inner-cmd heredoc and bakes the
    [messages.pass2_exit] strings as literals at Pass-1 install
    time -- the heredoc's spawned pwsh has no toml access yet
    (runs before M:\ overlay is staged).

Author: Kabuki94

usr/share/mios/mios.toml

@@ -267,6 +267,28 @@ lines = [
 linear_log_note = "Note: console doesn't support in-place repaint -- running in linear log mode."
 linear_log_hint = "      Phase transitions + throttled step updates print sequentially below."
 
+# ----------------------------------------------------------------------------
+# [messages.elevation] -- Pass-1 -> Pass-2 UAC handoff prompts.
+# The operator sees these immediately before the UAC dialog fires.
+# ----------------------------------------------------------------------------
+[messages.elevation]
+admin_required   = "  [*] MiOS bootstrap requires admin (M:\\ partition + Podman + dev VM)."
+uac_trigger_line = "  [*] Triggering UAC -- accept to continue. The install will then run"
+uac_trigger_hint = "      in the elevated window, single prompt only."
+
+# ----------------------------------------------------------------------------
+# [messages.pass2_exit] -- Pass-2 failure / completion / close-prompt
+# strings shown in the elevated bootstrap window after the install
+# returns (success or failure).  Operators rebrand the post-flow
+# narrative via mios.html.
+# ----------------------------------------------------------------------------
+[messages.pass2_exit]
+exited_code_prefix = "  [!] Bootstrap exited with code "
+failure_detail     = "      Output above is the failure detail (Pass-1 has no separate log)."
+build_log_hint     = "      build-mios.ps1's own log at M:\\MiOS\\logs\\mios-install-*.log only kicks in on Pass-2 success."
+fetch_run_failed   = "  [!] Bootstrap fetch/run failed: "
+press_enter_close  = "  Press Enter to close this elevated bootstrap window..."
+
 # ----------------------------------------------------------------------------
 # [messages.install_complete] -- end-of-bootstrap operator-facing
 # summary banner.  Title + bullets are operator-tunable; verb hints