# Stocks in the Future — system map

An edit map of this Rails app: what the nouns are, how they move, and what else moves
when you change one. **The app tree is the source of truth** — cards cite `path:line`
and never restate behaviour. Read a card, then read the source it points at.

Built on ICM: folders carry sequencing, hierarchy carries context, files carry state.

## Where things live

| Folder | What it holds |
|---|---|
| `objects/` | one card per noun, clustered by how an editor asks |
| `processes/` | the six movements that actually run |
| `effects/` | change-impact index — "changing X? open these cards" |
| `_meta/` | schema: the closed set of node types and labels |
| `_templates/` | blank object/process cards — a new card is a copy |

## Route by what you are doing

| If you are… | Go to | Then stop at |
|---|---|---|
| orienting cold | `CONTEXT.md` | universes + traps, then one card |
| asking "what is X?" | `objects/_index.md` | the one card it names |
| asking "how does X happen?" | `processes/CONTEXT.md` | the one movement card |
| about to change something | `effects/CONTEXT.md` | the cards it lists |
| checking coverage | `objects/_index.md` | `status:` column |

## Names that collide

Read this table before editing. Full detail and citations: `CONTEXT.md`.

| You will hear | It actually is |
|---|---|
| "SIF dollars" | `portfolio_transactions.amount_cents` — integer cents, no `Money` type |
| "balance" | derived, never stored. `portfolios` has **no cash column** |
| "grade" | two things: `Grade` = level 5–8; `GradeEntry#math_grade` = letter `"A+"`..`"F"` |
| "admin" | a boolean column, **not** an STI type. Only `Student`/`Teacher` are types |
| "log in" | by `username`, **not** email |
| "the student's classroom" | two rival paths: `users.classroom_id` **and** `classroom_enrollments` |
| "Stocks for Good" | same app. Code says `StocksInTheFuture` |

## The one rule

A card may be wrong; the source cannot. If a card and the code disagree, the code wins —
fix the card the same day and set `status: stale` if you cannot.

---
`AGENTS.md` and `routing.md` are generated copies of this file. Never hand-edit them —
edit `CLAUDE.md` and run `_meta/sync-twins.sh`.