fix(approvals,l10n,theme): usertest findings — localized prompts, no-data confirm, .chain log path, honest wording, AA contrast

- approvals: empty/legacy hub prompts render the localized fallback;
  approving without show: data asks for conscious confirmation first
- chain_log: write to ~/.chain/logs/studio-errors.log (was .fai),
  one-time best-effort migration of the legacy file + rotation sibling
- l10n: 'manipulationssicher' -> 'manipulationserkennend', neutral
  WORM-1 blurb, doctor pill 'Integritätskette v1', federation hint
  says the CA authenticates the first connect (DE+EN)
- theme: muted text token now >=4.5:1 on canvas, cards and elevated
  dark surfaces (was 3.7:1 on cards)

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/l10n/app_en.arb

@@ -49,7 +49,7 @@
   "welcomeDocSecurityTitle": "Sandbox model",
   "welcomeDocSecurityBlurb": "What a module declares, what the operator caps, what the hub enforces.",
   "welcomeDocAuditTitle": "Tamper-evident audit log",
-  "welcomeDocAuditBlurb": "How the hash chain works and why WORM-1 is enough for KRITIS.",
+  "welcomeDocAuditBlurb": "How the hash chain makes later edits detectable — and what integrity level WORM-1 does (and does not) provide.",
   "welcomeDocFlowsTitle": "Flow composition",
   "welcomeDocFlowsBlurb": "YAML basics, templating reference, the extract→summarize example.",
   "welcomeDocApprovalsTitle": "Approvals",
@@ -1064,6 +1064,9 @@
   "approvalsPillExpired": "expired",
   "approvalsPayloadPreview": "DATA TO REVIEW",
   "approvalsNoPayload": "No data was attached for review. The flow's approval step chooses what to show via its \"show:\" field — set it to surface the data behind this decision.",
+  "approvalsNoDataConfirmTitle": "Approve without review data?",
+  "approvalsNoDataConfirmBody": "This flow deliberately attached no review data (no \"show:\" on its approval step). You can still approve — but you would be deciding without seeing the data behind this decision.",
+  "approvalsNoDataConfirmAction": "Approve anyway",
   "approvalsRequestFallback": "Approval required for this step",
   "approvalsFlowStepMeta": "Flow: {flow} · Step: {step}",
   "@approvalsFlowStepMeta": {
@@ -1217,7 +1220,7 @@
       }
     }
   },
-  "doctorChainPillOk": "WORM-1",
+  "doctorChainPillOk": "Integrity chain v1",
   "doctorChainPillTamper": "TAMPER",
   "doctorVerifyNow": "Verify now",
   "doctorRestart": "Restart",
@@ -1700,5 +1703,5 @@
   "federationTokenLabel": "Bootstrap token (single use)",
   "federationConfigLabel": "Satellite config (paste into the satellite)",
   "federationCopied": "Copied to clipboard",
-  "federationEnrollmentHint": "Hand the token to the satellite operator over a secure channel. The bundled CA makes the satellite's first connect tamper-proof."
+  "federationEnrollmentHint": "Hand the token to the satellite operator over a secure channel. The bundled CA authenticates the satellite's first connect."
 }