Harden Anker Solix OCPP control (token hashing, step-up, audit, TLS)

Security pass over the OCPP charger-control feature added in a1519f6, since
remotely actuating a physical charger is a real side effect.

Token hygiene:
  - Per-charger control tokens are stored as SHA-256 hashes + a last-4 hint,
    never plaintext. The token is shown once at generation; the status endpoint
    returns only the hint. Added a revoke endpoint that also drops any live
    session using the revoked token.

Step-up + confirmation:
  - Destructive actions (reset, unlock) require confirm:true AND a password
    re-authentication (verified against PocketBase). The Charging UI collects the
    password inline for reset.
  - Per user+charger rate limit (30/min) on control commands.

Transport + provenance:
  - OCPP_REQUIRE_TLS (default on) rejects plaintext ws:// charger connections;
    OCPP_PUBLIC_URL pins the advertised endpoint instead of trusting request
    headers.
  - Proxy-mode upstream URL is validated against a *.anker.com allowlist, so a
    spoofed ocpp-info response can't redirect the proxy.

Durable audit:
  - New control_audit PocketBase collection (added to setup-pocketbase.mjs);
    every control action, token generate/revoke and charger connect is persisted
    best-effort in addition to a structured log line.

Startup:
  - The control-token index is warmed from PocketBase on startup so a charger
    reconnecting after a restart resolves immediately.

Tests:
  - Unit tests for token hashing/eviction/revoke (no plaintext at rest),
    rate limiter, destructive-action classifier, upstream allowlist, TLS
    enforcement, and re-auth guards. A full-stack E2E (control_e2e_test.go)
    drives the real Handler with a stand-in PocketBase and a simulated charge
    point, proving step-up (400/401/200) and audit persistence end to end.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

API Server/internal/api/integrations_ankersolix.go

@@ -60,12 +60,15 @@ type ankerConfig struct {
 	ControlMode string `json:"controlMode"`
 }
 
-// ankerChargerBinding is the per-charger OCPP control token an operator installs
-// into the charger (as the OCPP Basic-auth password) so it may connect to the
-// DriverVault CSMS. It is user-layer only — not a cascade credential.
+// ankerChargerBinding records a per-charger OCPP control token. The operator
+// installs the token into the charger (as its OCPP Basic-auth password); we keep
+// only its SHA-256 hash and a short hint, never the plaintext — the token is
+// shown to the owner exactly once, at generation. User-layer only, not a cascade
+// credential.
 type ankerChargerBinding struct {
-	Token   string `json:"token"`
-	AddedAt string `json:"addedAt,omitempty"`
+	TokenHash string `json:"tokenHash,omitempty"` // sha256(token), lowercase hex
+	TokenHint string `json:"tokenHint,omitempty"` // last 4 chars, for the UI
+	AddedAt   string `json:"addedAt,omitempty"`
 }
 
 // ankerStored is what we persist per user/org under pluginSettings.ankerSolix.