Rebrand as Semantika with honest, inspiration-based claims

Applies the brand platform consistently across the codebase:

- Name: Semantika everywhere — app name/slug/scheme, bundle ids
  (com.semantika.app), workspace package names, CDK stack, Cognito
  domain prefix, secret name (semantika/app), database name, product
  ids (semantika_monthly/_yearly), and storage keys.
- System instructions: Semantika is positioned as an intelligent
  reflection partner — not therapy, not self-help, not a course. It
  starts by exploring how the user interprets their situation and
  supports reflection and perspective-taking rather than delivering
  finished answers. Tone rules added: never judging, dramatic,
  overenthusiastic or preaching; always calm, curious, clear,
  respectful, structured, thoughtful.
- Honest claims: instructions and knowledge base now explicitly frame
  neurosemantics and NLP as models and inspiration for reflection, not
  scientifically established methods — including a note that several
  NLP claims lack support in controlled studies. Claiming or implying
  proven effects is forbidden.
- README: brand section (position, promise, mission, vision,
  positioning, tone, design words) and updated product philosophy.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0118DaxZR36RpnY524vRqx3z

infra/bin/semantika.ts

@@ -1,9 +1,9 @@
 import { App } from 'aws-cdk-lib';
-import { NeuroSemanticsStack } from '../lib/neurosemantics-stack.js';
+import { SemantikaStack } from '../lib/semantika-stack.js';
 
 const app = new App();
 
-new NeuroSemanticsStack(app, 'NeuroSemantics', {
+new SemantikaStack(app, 'Semantika', {
   env: {
     account: process.env.CDK_DEFAULT_ACCOUNT,
     region: process.env.CDK_DEFAULT_REGION ?? 'eu-north-1',