docs: restructure TASKS.md into a catalog — one file per task in TASKS/

TASKS.md is now the index (status table, open items, research pointer).
33 files: 32 task files + 1 research facts file. The full take-saga
narrative and all design decisions are preserved verbatim; the catalog
makes the queue readable without opening every task body. Schema and
AGENTS.md updated to reflect the new layout.

schema.md

@@ -19,7 +19,7 @@ that every other memory file follows. Read `ai.md` first; this file explains
 | `AGENTS.md` | Auto-read on-ramp for AI sessions — points to the map and the working rules | **always read first** |
 | `README.md` | Human-facing intro: what the app is, how to run it, roadmap | no |
 | `ai.md` | **AI guide + session handoff** — architecture, patterns, decisions, the cognitive map home | **yes — start here** |
-| `TASKS.md` | Task queue + authoritative YouTube API research facts + task statuses | yes — for status |
+| `TASKS.md` | **Catalog/index** for the task queue. The actual task files live in [`TASKS/`](TASKS/) (one file per task); `TASKS.md` carries the status table, open items, and research facts pointer. Read this for queue state; open task files for full detail. | yes — for status |
 | `HANDOFF.md` | Current operational state: what's in flight, landmines, next step, secret/DB/port locations | yes — trust it as current state |
 | `MyMistakes.md` | Per-task failure log **+ RECIPES REGISTRY** (derived-solution rule): one-off solutions / how-tos get recorded here the same session, then grepp'd before ever re-deriving them (see `AGENTS.md` 🔬) | grep first on any "did this before?" wall |
 | `schema.md` | This file: the conventions below | when in doubt |