fix(examples): stop overriding the managed Intelligence URL defaults (closes OSS-981)

CopilotKitIntelligence resolves apiUrl/wsUrl to the managed hosts when they are
omitted, and its own docstring says leaving both unset is always correct against
the managed service. Every starter's runtime route supplied
`?? "http://localhost:4201"` instead, so a managed reader who copied the block
got a runtime aimed at a local stack that is not running -- the failure the
starter's own .env.example warns about two files away.

Replace the fallbacks with the conditional spread these same starters already use
in channel-host.mts, so a self-hosted override still works and the managed
default applies when it is absent. Three .env.example files also set the values
uncommented, two of them directly under a comment telling the reader to leave
them unset; comment those out to match the other nineteen starters.

Guard both shapes in validate-intelligence-env-names.ts, which already polices
the canonical Intelligence key name and hosts and runs unfiltered on every PR.
The rule is the pattern rather than the literal, so a staging host substituted
for localhost fails the same way. Local e2e harnesses and demo stacks that
genuinely target a local deployment are allowlisted with their reasons.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.github/workflows/static_intelligence-env-names.yml

@@ -37,5 +37,11 @@ jobs:
 
       - run: pnpm install --frozen-lockfile
 
+      # The rules are unit-tested here rather than by a general runner: nothing
+      # else executes scripts/__tests__, so a rule that silently stopped
+      # matching would leave the check below passing on an empty result.
+      - name: Test the validator's rules
+        run: pnpm exec vitest run scripts/__tests__/validate-intelligence-env-names.test.ts
+
       - name: Check Intelligence env var names are canonical
         run: pnpm check:intelligence-env-names