feat(pipeline): update system prompt for new LLM JSON contract (no slugs)

- Change prompt to reflect new output format: title, type, subtype, domain, content
- Remove slug/path generation responsibility from LLM — pipeline now handles it
- Wikilinks change from [[slug|Display Name]] to [[Display Name]] only
- LLM no longer includes frontmatter or paths in output

docs(schema): update LLM output format and wikilink convention for Level 3

- Specify JSON schema: title, type, subtype, domain, content fields
- Remove frontmatter requirements from schema output (handled by pipeline)
- Simplify wikilink format to [[Display Name]] — no slug or pipe
- Pipeline now responsible for slug generation and frontmatter construction

These changes shift slug/frontmatter generation from LLM to pipeline,
reducing cognitive load on the model and improving control over output.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

brain/schema.md

@@ -3,21 +3,34 @@
 This document defines the three page types in the brain wiki.
 The LLM must follow this schema exactly when generating wiki pages.
 
+## Output Format
+
+Return a JSON array. Each element:
+
+```json
+{
+  "title":   "exact page title",
+  "type":    "source | concept | entity",
+  "subtype": "see below — omit for concept",
+  "domain":  "see domains — omit if none fits",
+  "content": "Markdown body only — no frontmatter, no path"
+}
+```
+
+- `subtype` for **source**: `article | pdf | book | video | note | project`
+- `subtype` for **entity**: `person | company | tool | model | framework | technology`
+- The pipeline computes slugs and frontmatter — never include them in output.
+
 ## Wikilink Format
 
-All cross-references use `[[slug|Display Text]]`.
+All cross-references use `[[Display Name]]` — just the display name, no slug, no pipe.
 
 Rules:
-- slug = lowercase filename without .md, spaces → hyphens, strip all non-alphanumeric except hyphens
+- Only link to pages in the inventory or pages you are creating in this response
-- The `|` separator is REQUIRED — never use `[[Title]]` without a slug
+- The pipeline converts `[[Display Name]]` to `[[slug|Display Name]]` automatically
-- Examples: `[[domain-driven-design|Domain Driven Design]]`, `[[ryan-singer|Ryan Singer]]`
+- Section links must match their section type (Related Concepts → concept pages only, etc.)
-- Slugs must resolve to an existing file in the inventory, or a file you are creating in this response
 
-Slug generation examples:
+Examples: `[[Domain Driven Design]]`, `[[Ryan Singer]]`, `[[Shape Up]]`
-- "Domain Driven Design" → `domain-driven-design`
-- "It's Complicated" → `its-complicated`
-- "gRPC" → `grpc`
-- "GPT-4o" → `gpt-4o`
 
 ## Domains
 
@@ -30,17 +43,6 @@ Use one of: `ai-llm`, `software-engineering`, `product-strategy`, `finance-marke
 
 One page per ingested source. Books are NEVER split across multiple source pages — update the existing one.
 
-Required frontmatter:
-```yaml
-title: <exact title>
-type: article | pdf | book | video | note | project
-domain: <domain>
-date_ingested: YYYY-MM-DD
-last_updated: YYYY-MM-DD
-aliases:
-  - <exact title>
-```
-
 Body sections (in this order):
 
 ### Summary
@@ -50,10 +52,10 @@ Body sections (in this order):
 Bulleted list. Paraphrase — no verbatim quotes or code.
 
 ### Concepts Introduced or Reinforced
-Wikilinks to wiki/concepts/ ONLY. One per line.
+Wikilinks to concept pages ONLY. One per line.
 
 ### Entities Mentioned
-Wikilinks to wiki/entities/ ONLY. One per line.
+Wikilinks to entity pages ONLY. One per line.
 
 ### Open Questions Raised
 Gaps or follow-up questions from this source.
@@ -75,15 +77,6 @@ Dated entries appended on re-ingestion. NEVER rewrite — only append.
 
 One page per idea, framework, methodology, or pattern.
 
-Required frontmatter:
-```yaml
-title: <concept name>
-domain: <domain>
-last_updated: YYYY-MM-DD
-aliases:
-  - <exact title>
-```
-
 Body sections (in this order):
 
 ### Definition
@@ -93,13 +86,13 @@ One-paragraph plain-language explanation.
 Practical significance. Why should anyone care?
 
 ### Related Concepts
-Wikilinks to wiki/concepts/ ONLY.
+Wikilinks to concept pages ONLY.
 
 ### Related Entities
-Wikilinks to wiki/entities/ ONLY.
+Wikilinks to entity pages ONLY.
 
 ### Sources
-Wikilinks to wiki/sources/ ONLY.
+Wikilinks to source pages ONLY.
 
 ### Evolving Notes
 Updated as new sources arrive. Append, do not rewrite.
@@ -110,16 +103,6 @@ Updated as new sources arrive. Append, do not rewrite.
 
 One page per person, tool, organisation, technology, or product.
 
-Required frontmatter:
-```yaml
-title: <name>
-type: person | company | tool | model | framework | technology
-domain: <domain>
-last_updated: YYYY-MM-DD
-aliases:
-  - <exact title>
-```
-
 Body sections (in this order):
 
 ### Description
@@ -132,23 +115,23 @@ Why this entity matters to this knowledge base.
 With dates where known.
 
 ### Related Concepts
-Wikilinks to wiki/concepts/ ONLY.
+Wikilinks to concept pages ONLY.
 
 ### Related Entities
-Wikilinks to wiki/entities/ ONLY.
+Wikilinks to entity pages ONLY.
 
 ### Sources
-Wikilinks to wiki/sources/ ONLY.
+Wikilinks to source pages ONLY.
 
 ---
 
 ## Non-Negotiable Rules
 
 1. Output ONLY a valid JSON array — no markdown fences, no prose before or after
-2. Each element: `{"path": "wiki/<type>/<slug>.md", "content": "...full markdown..."}`
+2. Each element: `{"title": "...", "type": "...", "subtype": "...", "domain": "...", "content": "..."}`
-3. Slugs are kebab-case: lowercase, spaces→hyphens, strip special characters
+3. Never include slugs, paths, or frontmatter in output — the pipeline handles these
-4. Every wikilink must be `[[slug|Display Text]]` — the pipe separator is required
+4. Wikilinks: `[[Display Name]]` only — no pipe, no slug
-5. Dates always YYYY-MM-DD
+5. Dates always YYYY-MM-DD (used only in content body where contextually relevant)
 6. Never reproduce verbatim code — describe the pattern or technique
-7. Section links must match their section type (Related Concepts → concepts/ only, etc.)
+7. Section links must match their section type
 8. One source page per book — if inventory shows it exists, include it as an UPDATE

ingestion/internal/pipeline/prompt.go

@@ -12,12 +12,15 @@ import (
 const systemPrompt = `You are a wiki agent. Read the source material and produce structured wiki pages following the schema provided.
 
 Output ONLY a valid JSON array — no markdown fences, no other text before or after.
-Each element must have:
+Each element must have exactly these fields:
-  "path"    — relative path within the wiki, e.g. "wiki/sources/foo.md"
+  "title"   — exact page title (e.g. "FinBERT", "Ryan Singer", "Shape Up")
-  "content" — full markdown content of the page including YAML frontmatter
+  "type"    — exactly one of: "source", "concept", "entity"
+  "subtype" — for source: article|pdf|book|video|note|project; for entity: person|company|tool|model|framework|technology; omit for concept
+  "domain"  — one of the domains in the schema (omit if none fits)
+  "content" — Markdown body only — NO frontmatter, NO path, NO slug
 
-Follow the schema strictly: correct frontmatter fields, wikilinks as [[slug|Display Text]],
+Wikilinks in content: [[Display Name]] — just the display name, no slug, no pipe separator.
-dates in YYYY-MM-DD format, and paraphrase rather than quoting verbatim.`
+Only link to pages listed in the inventory or pages you are creating in this response.`
 
 // BuildPrompt constructs the user prompt for a single chunk.
 func BuildPrompt(schema, source, content string, inventory map[wiki.PageType][]wiki.Entry) string {
@@ -30,7 +33,7 @@ func BuildPrompt(schema, source, content string, inventory map[wiki.PageType][]w
 	sb.WriteString("\n\n")
 
 	sb.WriteString("## Existing wiki pages\n\n")
-	sb.WriteString("Link ONLY to pages in this inventory or pages you are creating in this response.\n\n")
+	sb.WriteString("Reference these pages by display name only — [[Display Name]] — in your content.\n\n")
 
 	for _, pt := range []wiki.PageType{wiki.PageTypeConcept, wiki.PageTypeEntity, wiki.PageTypeSource} {
 		entries := inventory[pt]
@@ -39,19 +42,19 @@ func BuildPrompt(schema, source, content string, inventory map[wiki.PageType][]w
 			fmt.Fprintf(&sb, "%s — (none yet)\n\n", label)
 			continue
 		}
-		fmt.Fprintf(&sb, "%s — link ONLY under the matching section:\n", label)
+		fmt.Fprintf(&sb, "%s:\n", label)
 		for _, e := range entries {
-			fmt.Fprintf(&sb, "  - [[%s|%s]]\n", e.Slug, e.Title)
+			fmt.Fprintf(&sb, "  - %s\n", e.Title)
 		}
 		sb.WriteString("\n")
 	}
 
 	sb.WriteString("## Non-negotiable rules\n\n")
 	sb.WriteString("1. Output ONLY a valid JSON array — no prose, no fences.\n")
-	sb.WriteString("2. Slugs are kebab-case: lowercase, spaces→hyphens, no special chars.\n")
+	sb.WriteString("2. Fields: title, type, subtype (if applicable), domain (if applicable), content.\n")
-	sb.WriteString("3. Wikilinks: [[slug|Display Text]] — the pipe is required.\n")
+	sb.WriteString("3. Wikilinks: [[Display Name]] — no slug, no pipe. The pipeline handles slugs.\n")
-	sb.WriteString("4. Section links must match their section type.\n")
+	sb.WriteString("4. Section links must match their section type (Related Concepts → concepts only, etc.).\n")
-	sb.WriteString("5. One source page per book — update it if inventory shows it exists.\n\n")
+	sb.WriteString("5. One source page per book — if inventory shows it exists, return it as an UPDATE.\n\n")
 
 	fmt.Fprintf(&sb, "## Source: %s\n\n", source)
 	sb.WriteString(content)