docs: add Obsidian Bases plugin documentation to system prompt

Add comprehensive documentation for the Obsidian Bases core plugin including file structure, property namespaces, filter syntax, formula syntax, view configuration, and usage guidelines.

AIPrompts/SystemPrompt.ts

@@ -257,6 +257,96 @@ When searches return or reference images or PDFs:
 
 ---
 
+## Obsidian Bases
+
+**Bases** is a core plugin (available since Obsidian 1.9) that creates database-like views of notes from their YAML frontmatter properties. Bases are stored as \`.base\` files — treat them like notes: reference with \`[[MyBase.base]]\`, embed with \`![[MyBase.base]]\` or \`![[MyBase.base#ViewName]]\`.
+
+### When to Use Bases
+- User wants to view, filter, or aggregate notes by their properties (status, tags, dates, etc.)
+- User asks to "create a database / tracker / table" of notes
+- User wants computed columns or summaries across multiple notes
+
+### File Structure
+\`.base\` files are YAML with five top-level sections:
+\`\`\`yaml
+filters:        # Which notes to include (global, all views)
+formulas:       # Computed properties derived from other properties
+properties:     # Display names / config for columns
+summaries:      # Custom summary formulas for aggregations
+views:          # One or more named views (table, cards, list, map)
+\`\`\`
+
+### Property Namespaces
+| Namespace | Access | Example |
+|-----------|--------|---------|
+| Note frontmatter | \`property\` or \`note.property\` | \`status\`, \`note.author\` |
+| File metadata | \`file.*\` | \`file.name\`, \`file.mtime\`, \`file.size\` |
+| Formula results | \`formula.*\` | \`formula.days_left\` |
+| Current context | \`this.*\` | \`this.file.path\` (see \`this\` behavior below) |
+
+### The \`this\` Context
+\`this\` resolves differently depending on how the base is opened:
+- **Standalone tab**: \`this\` points to the base file itself
+- **Embedded in a note** (\`![[MyBase.base]]\`): \`this\` points to the embedding file
+- **Opened in the sidebar**: \`this\` points to the active file in the main content area
+
+### Filter Syntax
+\`\`\`yaml
+# Single condition
+filters: 'status == "done"'
+# Boolean logic
+filters:
+  and:
+    - 'file.hasTag("project")'
+    - 'status != "archived"'
+  or:
+    - 'priority > 3'
+    - not:
+        - 'file.inFolder("Archive")'
+\`\`\`
+
+Key filter functions: \`file.hasTag("tag")\`, \`file.hasLink("NoteName")\`, \`file.inFolder("FolderName")\`, \`file.path == this.file.path\`
+
+### Formula Syntax
+\`\`\`yaml
+formulas:
+  days_left:   'date(due) - now()'
+  overdue:     'if(date(due) < now(), "⚠️", "")'
+  word_count:  '(file.size / 5).round(0)'
+\`\`\`
+
+### View Structure
+\`\`\`yaml
+views:
+  - type: table          # table | cards | list | map
+    name: "Active"
+    limit: 50
+    groupBy:
+      property: status
+      direction: ASC
+    filters:
+      and:
+        - 'status != "done"'
+    order:
+      - file.name
+      - status
+      - formula.days_left
+\`\`\`
+
+### Creating a Base
+- **Command Palette**: \`Bases: Create new base\` (creates a new standalone base file)
+- **File Explorer**: Right-click a folder → *New base*
+- **Manual**: Create a file with \`.base\` extension and write YAML directly
+
+### Key Rules
+- All data stays in Markdown frontmatter — Bases are a view layer, not a separate database
+- \`this\` resolves to the base file, embedding file, or active file depending on context (see above)
+- Bases replace most Dataview use cases; prefer Bases for new vault database needs
+- Wiki-link bases like notes: \`[[ProjectTracker.base]]\`
+\`\`\`
+
+---
+
 ## Multi-Tool Workflow Architecture
 
 ### Direct Execution (Default Mode)