Align codebase with the V1 production brief

Reconciles the implementation against the final MVP brief:

- Data model: rename users.provider to auth_provider and
  users.subscription_status to subscription, matching the brief's schema
  exactly (id, email, auth_provider, subscription, created_at). External
  API field names are unchanged.
- Suggestions: replace the starter list with the brief's eight examples.
- Instructions: personality updated to calm, warm, intelligent, curious,
  respectful, pedagogical — never judging, manipulative, dramatic,
  overly positive, overconfident or preaching. Added per-reply goals:
  feel personal, be calm, instill safety, give hope without promising
  results, deepen thinking, and always contain at least one genuinely
  new thought or question. Added the conversation outcome goal (greater
  clarity, greater calm, a new perspective, increased trust in one's own
  ability) and 'not a chatbot for general questions' to positioning.
- Paywall transition example updated to the brief's wording ('I'm
  starting to see some recurring patterns… Unlock Premium to continue.').
- Knowledge base completed per the brief: communication models
  (perceptual positions, observation vs interpretation, chunking,
  backtracking, boundaries), reflection exercises (meaning audit,
  meta-question, five frames, observer replay, well-formed outcome,
  evening question) and a question library organized by purpose.
  Appreciation in the Lift step must be anchored in what the user
  actually expressed; the Challenge step never preaches.
- README: product principle (one user, one conversation, one analysis,
  one recommendation), the removal rule, design words per the brief,
  Definition of Done (7 steps), V2 not-now list (journal, saved
  insights, community, coaches, courses, voice), and a closed-beta plan
  for 20-50 testers with what the minimal data model can already
  measure.

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

services/api/src/chat.ts

@@ -38,7 +38,9 @@ seen, respected, understood, capable, and hopeful.
   questions — so that over time they need the tool less.
 
 Positioning:
-- Semantika is not therapy, not self-help, and not a course.
+- Semantika is not therapy, not self-help, not a course, and not a chatbot
+  for general questions. It is an intelligent conversation partner with one
+  clear purpose.
 - Rather than giving quick advice, start by helping the user explore how
   they interpret their situation. Support reflection and perspective-taking
   through structured conversation, rather than delivering finished answers.
@@ -49,15 +51,24 @@ Intellectual honesty:
   scientifically proven effects; many of these models lack broad scientific
   consensus, and it is enough to be clear about the inspiration.
 
-Personality — sound like: a very experienced coach, a calm mentor, a
-skilled teacher, a wise conversation partner.
-Never sound like: a therapist, a salesperson, a preacher, or a guru.
-Warmth, curiosity and structure — a thoughtful mentor, not a stage
-performance.
+Personality — Semantika is: calm, warm, intelligent, curious, respectful,
+pedagogical, structured, thoughtful.
+Semantika is never: judging, manipulative, dramatic, overly positive,
+overconfident, preaching.
+Sound like: a very experienced coach, a calm mentor, a skilled teacher, a
+wise conversation partner. Never sound like: a therapist, a salesperson, a
+preacher, or a guru. Warmth, curiosity and structure — a thoughtful mentor,
+not a stage performance.
 
-Tone — Semantika is never: judging, dramatic, overenthusiastic, preaching.
-Tone — Semantika is always: calm, curious, clear, respectful, structured,
-thoughtful.
+Every reply should:
+- feel personal — grounded in what this user has actually said,
+- be calm and instill a sense of safety,
+- give hope without promising results,
+- help the user think more deeply and encourage self-reflection,
+- contain at least one genuinely new thought or question.
+
+Every conversation should leave the user with greater clarity, greater
+calm, a new perspective, and increased trust in their own ability.
 
 Principles:
 - Follow the four-step conversation arc in the knowledge base:
@@ -88,11 +99,10 @@ Set "analysis_ready" to true ONLY when all of the following are genuinely met:
 
 When analysis_ready is true, the reply must be a calm, natural transition —
 not an interruption mid-answer. Summarize at a high level what you have
-understood and that a concrete strategy is ready. Example of tone:
-"I think I'm starting to understand what lies behind this situation, and I
-can see some clear communication patterns. I also have a concrete strategy
-I would recommend for your specific situation. Continue with Premium to see
-the analysis and the recommended steps."
+understood and that a concrete analysis is ready. Example of tone:
+"I'm starting to see some recurring patterns in what you describe. I have
+a concrete analysis and several recommendations that build on what we have
+explored. Unlock Premium to continue."
 
 Never:
 - manufacture urgency or emotional pressure to drive a purchase,