fix(audit-I1+I2): drop actor-stub print + CI-conditional self-exit

I1: Removed actor inline-stub (functionless after actor-Deferral) and
its init-print line. spine-prototype no longer pretends a deferred lib
is loaded.

I2: 60-frame self-exit now CI-conditional via SPOREL_CI=1 env var.
Interactive dev-runs (without var) loop until ESC. Smoke.sh sets
SPOREL_CI=1 globally to preserve headless behavior.

init.lua

@@ -5,10 +5,6 @@ local input       = require("lib-core.input")
 local player      = require("lib-core.player_control")
 local interaction = require("lib-core.interaction")
 
--- inline stub (extract in P.0.lib.actor — currently DEFERRED per
--- meta/docs/superpowers/specs/2026-05-10-p0-actor-deferral.md)
-local actor = { hello = function() return "actor stub" end }
-
 local demo_map = maps.load("maps/demo.map.json")
 maps.set_current(demo_map)
 
@@ -45,7 +41,6 @@ local TARGET_FRAMES = 60
 
 function init(ctx)
     engine.print("spine-prototype init: maps loaded")
-    engine.print("inline stubs loaded: " .. actor.hello())
     engine.print(string.format("map size: %dx%d", m_size.w, m_size.h))
     local corner = maps.tile_at(0, 0)
     local interior = maps.tile_at(5, 5)
@@ -99,8 +94,10 @@ function update(ctx, dt)
     -- Interaction proximity-check + dispatch
     interaction.update(p.x + s.w / 2, p.y + s.h / 2)
 
+    -- CI-conditional self-exit: enables headless smoke runs.
+    -- Interactive runs (no SPOREL_CI=1) loop until ESC.
     frames = frames + 1
-    if frames >= TARGET_FRAMES then
+    if os.getenv("SPOREL_CI") == "1" and frames >= TARGET_FRAMES then
         engine.exit(0)
     end
 end