refact(deployer): one MainPID gate for all three LLM endpoints

frank-dragoon's health gate never checked WHO answered :7770 — the
false-green the fleet learned about on 2026-09-26 (a stray probe holding
the port satisfies a bare curl while the unit is stopped). The other two
handlers carried that check as inlined copies; all three now call
assert_unit_owns_port, and dragoon gets the protection it was missing.

The seam follows: the endpoints' text-grep deployer tests are deleted,
because tests/llm_deploy_gates.bats EXECUTES the same handlers end to end
(stub systemctl/podman/sudo/ss/curl) and asserts refusals, restarts, unit
links, the pending marker, and the MainPID hardening. GATE_PREFIX is
exported at each handler for the same reason the serve scripts export it.

tests/frank_zealot_unit.bats

@@ -269,17 +269,6 @@ run_stage() {
     [[ "$output" == *"build-llama-master-cuda.sh"* ]]
 }
 
-@test "the deploy handler gates on binary, GGUF and projector, then MainPID-hardens health" {
-    grep -q 'deploy_llm_zealot' "$REMOTE_DEPLOY"
-    grep -q 'LLM_ZEALOT_RUNTIME' "$REMOTE_DEPLOY"
-    grep -q 'LLM_ZEALOT_MODEL_FILE' "$REMOTE_DEPLOY"
-    grep -q 'LLM_ZEALOT_MMPROJ' "$REMOTE_DEPLOY"
-    grep -q 'relink_unit frank-zealot' "$REMOTE_DEPLOY"
-    grep -q 'systemctl enable frank-zealot.service' "$REMOTE_DEPLOY"
-    grep -q '127.0.0.1:7771/health' "$REMOTE_DEPLOY"
-    grep -q 'frank-zealot.service has no MainPID' "$REMOTE_DEPLOY"
-}
-
 @test "the two endpoints keep separate ports and the large handler never pkills llama-server" {
     # frank-dragoon's sweeps must not take down frank-zealot, whose
     # process is llama-server on the SAME host.