docs(skills): drop the duplicated ASCII field-type decision tree from objectstack-data rules

skills/objectstack-data/rules/field-types.md

@@ -144,77 +144,6 @@ Stored as JSON on the parent row — no separate table / FK:
 | `tags` | Free-form tag input | — |
 | `vector` | AI/ML embeddings (semantic search, RAG) | `dimensions` (flat sibling, e.g. `1536`) |
 
-## Field Type Decision Tree
-
-```
-What kind of data?
-│
-├── Text?
-│   ├── Single line → text
-│   ├── Multiple lines → textarea
-│   ├── Formatted → richtext / markdown / html
-│   ├── Email → email
-│   ├── URL → url
-│   ├── Phone → phone
-│   ├── Credential (API key, token, DB password) → secret (encrypted at rest — NOT password)
-│   └── Code → code
-│
-├── Number?
-│   ├── Money → currency
-│   ├── Percentage → percent
-│   └── Generic → number
-│
-├── Date/Time?
-│   ├── Date only → date
-│   ├── Time only → time
-│   └── Date + Time → datetime
-│
-├── True/False?
-│   ├── Checkbox → boolean
-│   └── Switch → toggle
-│
-├── Choose from list?
-│   ├── Single choice, dropdown → select
-│   ├── Single choice, always visible → radio
-│   ├── Multiple choice, tags → multiselect
-│   └── Multiple choice, checkboxes → checkboxes
-│
-├── Reference another object?
-│   ├── Independent → lookup
-│   ├── Owned child → master_detail
-│   ├── A person (assignee, watcher) → user
-│   └── Hierarchy → tree
-│
-├── File/Media?
-│   ├── Image → image
-│   ├── Video → video
-│   ├── Audio → audio
-│   ├── User photo → avatar
-│   └── Generic file → file
-│
-├── Calculated?
-│   ├── Formula → formula
-│   ├── Roll-up → summary
-│   └── Auto-number → autonumber
-│
-├── Embedded sub-object (no separate table)?
-│   ├── Single → composite
-│   ├── Array → repeater
-│   └── Name-keyed map → record
-│
-└── Special?
-    ├── Location → location
-    ├── Address → address
-    ├── Color → color
-    ├── Rating → rating
-    ├── Signature → signature
-    ├── QR code → qrcode
-    ├── Progress → progress
-    ├── Tags → tags
-    ├── JSON data → json
-    └── AI embeddings → vector
-```
-
 ## Common Field Configurations
 
 ### Text with Max Length