Let a bot take any colour

A bot's identity was one of seven hues, and the hue picked both its colour
and its stone shape. Now its colour is free and its stone is its own:

- `bots.color` holds any `#rrggbb`, `bots.stone` the flat-cut shape it's
  drawn on. `bots.hue` stays as the palette column they replaced, read only
  as a fallback; `src/scripts/move-bot-colour-to-owners.ts` backfills an
  install from it (safe to rerun).
- `src/utils/bot-color.ts` is the only place a colour is validated or
  resolved (`resolveBotColor`/`resolveBotStone` carry the old hue forward,
  `botColorNeedsPaperFace` flips the eyes to paper on a very dark body), and
  `src/utils/bot-stone-props.ts` gives every row its props, so a row saved
  before this still renders as it did.
- `BotStone` takes the colour as the body's SVG `fill`, the one documented
  exception to the token rule: an arbitrary hex has no token to point at.
  `UnreadDot` follows it.
- The picker keeps the palette tiles (still shape and colour together) and
  adds a native swatch and a hex field, so a custom colour keeps its stone.
  Same place as before: the header avatar's modal and Settings > Bots, for
  crew managers. The coordinator stays hue-less.
- A recolour reaches other open tabs through `pushBotUpdated`.

src/schemas/bot-schema.ts

@@ -1,10 +1,10 @@
 import { z } from "zod";
 import { AppData } from "@/src/data/app-data";
 import {
-    BotHues,
     BotMessageReactions,
-    type BotHue,
+    BotStoneShapes,
     type BotMessageReactionEmoji,
+    type BotStoneShape,
 } from "@/src/dict/bot-dict";
 
 /**
@@ -115,7 +115,18 @@ export type ListBotSessionsRequest = z.infer<typeof ListBotSessionsRequestSchema
 export const CreateBotRequestSchema = z.object({
     name: z.string().trim().min(1, "Give the bot a name").max(40, "Keep the name under 40 characters"),
     role: z.string().trim().max(120, "Keep the role to one line").default(""),
-    hue: z.enum(BotHues.map((h) => h.value) as [BotHue, ...BotHue[]]),
+    /**
+     * Its identity colour, `#rrggbb`.
+     */
+    color: z
+        .string()
+        .trim()
+        .toLowerCase()
+        .regex(/^#[0-9a-f]{6}$/, "Pick a colour like #7c5cd6"),
+    /**
+     * Which flat-cut stone it's drawn on.
+     */
+    stone: z.enum(BotStoneShapes.map((s) => s.value) as [BotStoneShape, ...BotStoneShape[]]),
     system_prompt: z
         .string()
         .trim()