docs(modules): mirror the rest of the Oxide ecosystem, and add a machine-readable set

Completes the uMod mirror beyond the Rust hook table, and adds agent/ — the
same facts in TSV/JSONL at ~46% of the tokens.

New prose:
- OXIDE_API.md: the 19 developer pages under umod.org/documentation/api/ —
  plugin structure, hooks, commands, IPlayer, permissions, config, data files,
  database, localization, timers, web requests, dependencies, integration,
  preprocessor directives, security, style guide, CI, review. This is the
  framework our plugin is a guest in, where HOOKS.md is what the game says.
- OPERATING.md: the 6 operator pages — installing Oxide on a server, then
  installing, configuring and permissioning plugins.

New machine-readable set (agent/):
- hooks.tsv    477 rows, ~31% of HOOKS.md
- items.tsv    678 rows, ~80% of DEFINITIONS.md's item table
- skins.tsv    104 rows covering 2,590 skins, ~77%
- api.jsonl    150 code examples, ~47% of the two prose docs
Generated in the same pass as the markdown, so the two cannot drift.

HOOKS.md gains the universal-hook split: 34 of the 477 are uMod's own
Covalence hooks, raised identically on every game uMod supports. Verified
against /documentation/games/universal in the same capture - all 34 are in
the Rust set and the Rust page adds none of its own, so the overlap is exact.
The distinction is architectural: a universal hook is the portable part of
the surface.

Two things worth recording from building it:
- The first skins.tsv was one row per skin and came out 11% LARGER than the
  markdown it replaces. Grouping it one row per item is what made it a
  saving. The token win is real for prose (3.2x on hooks) and small for
  tables that were already dense - agent/README.md says so plainly rather
  than claiming a flat number.
- Signature extraction by brace depth silently captured body lines (a nested
  '}' in OnUserConnected's example ended the block early). It now matches on
  the hook's own name; all 477 rows verified to carry a real signature.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016wDDVXWMDz82WqE1i969r4

modules/rust/agent/README.md

@@ -0,0 +1,114 @@
+# `agent/` — the same reference, in machine shape
+
+The four files here carry **the same facts** as the markdown one directory up, stripped of prose and
+formatting so a coding agent can load or grep them cheaply. They are generated from the same scrape,
+in the same pass — they are not a separate capture and cannot drift from it.
+
+| File | Rows | Replaces | ~tokens | vs. the markdown |
+|---|---:|---|---:|---:|
+| [`hooks.tsv`](hooks.tsv) | 477 | [`../HOOKS.md`](../HOOKS.md) | ~19.6k | **31%** |
+| [`items.tsv`](items.tsv) | 678 | [`../DEFINITIONS.md`](../DEFINITIONS.md) § Items | ~6.9k | 80% |
+| [`skins.tsv`](skins.tsv) | 104 | [`../DEFINITIONS.md`](../DEFINITIONS.md) § Skins | ~17.9k | 77% |
+| [`api.jsonl`](api.jsonl) | 150 | [`../OXIDE_API.md`](../OXIDE_API.md) + [`../OPERATING.md`](../OPERATING.md) | ~7.8k | **47%** |
+| **Total** | | | **~52k** | **46%** |
+
+Token counts are `len(chars)/4` estimates, not a real tokenizer — accurate enough to choose a file,
+not to budget a context window.
+
+> **Be honest about where the win is.** It is large for hooks (3.2×) and the API prose (2.1×),
+> because both are mostly explanation. It is modest for the item and skin tables (~1.25×), because
+> `DEFINITIONS.md` is *already* a dense table — there was not much ceremony left to strip. The first
+> attempt at `skins.tsv` was one row per skin and came out **11% larger** than the markdown it was
+> meant to replace; grouping it one row per item is what made it a saving at all.
+
+---
+
+## Which file to reach for
+
+- **"Which hook fires when X happens?"** → `hooks.tsv`. It is the whole catalogue; grep the
+  description column.
+- **"What exactly does this hook give me, and what may I return?"** → `hooks.tsv` answers both in
+  the `signatures` and `returns` columns. Only go to `../HOOKS.md` for the worked example body.
+- **"How do I do <Oxide thing> in a plugin?"** → `api.jsonl`, grep `section` or `code`. It is every
+  code example uMod publishes, addressed by page and heading.
+- **"What is this item's id / short name?"** → `items.tsv`.
+- **"What skins exist for this item?"** → `skins.tsv`, one grep, one line.
+
+Read the markdown instead when you want the *reasoning* — the return-contract rules, the callouts,
+the cautions. Those are deliberately not in here.
+
+---
+
+## Formats
+
+All files are UTF-8 with LF endings and a header line. TSV fields are **tab-separated with no
+quoting and no escaping** — tabs and newlines are stripped from values at generation time, so a
+naive `split('\t')` is always correct.
+
+### `hooks.tsv`
+
+```
+name  category  universal  returns  signatures  description
+```
+
+- **`category`** — one of the 20 uMod subcategories (`Server`, `Player`, `Entity`, …).
+- **`universal`** — `1` for the 34 uMod *universal* (Covalence) hooks, which fire identically on
+  every game uMod supports; empty for Rust-specific ones. This is the portable/non-portable split.
+- **`returns`** — the return contract, normalised to one of five codes:
+
+  | Code | uMod's wording | What to declare |
+  |---|---|---|
+  | `none` | *No return behavior* | `void`. Nothing you return is read. |
+  | `nonnull` | *Returning a non-null value overrides default behavior* | `object`. `null` proceeds; anything else cancels. |
+  | `bool` | *Returning true or false overrides default behavior* | `object`. `null` abstains — `false` is **not** abstaining. |
+  | `data` | *Returning a string will kick…*, and similar | The value is consumed as data, not just as a veto. |
+  | `?` | upstream states no return behaviour at all | 3 hooks. Not a guess — genuinely absent. |
+
+- **`signatures`** — every declaration uMod publishes for the hook, joined by ` ;; `. Twelve hooks
+  have more than one (overloads); the rest have exactly one. Extracted by matching the hook's own
+  name, so no body line is ever mistaken for a signature.
+- **`description`** — the descriptive bullets, joined by `; `, with the return-behaviour bullet
+  moved into `returns`.
+
+### `items.tsv`
+
+```
+shortname  item_id  display_name
+```
+
+Sorted by short name. **`shortname` is the only key safe to persist** — see
+[`../DEFINITIONS.md`](../DEFINITIONS.md) § Which key to use.
+
+### `skins.tsv`
+
+```
+item_shortname  skins (id=name;id=name;...)
+```
+
+**One row per item, not per skin** — 104 rows covering 2,590 skins. A `;` inside a skin name is
+replaced with `,` so the field splits cleanly.
+
+### `api.jsonl`
+
+One JSON object per line, one object per code example uMod publishes:
+
+```json
+{"page":"api/timers","section":"Single timer","lang":"csharp","code":"timer.Once(1f, () =>\n{\n    Puts(\"Hello world!\");\n});"}
+```
+
+- **`page`** — the uMod path, e.g. `api/permissions`. Prefix with `https://umod.org/documentation/`
+  for the source.
+- **`section`** — the nearest heading above the example.
+- **`lang`** — `csharp`, `json` or `text`.
+
+This is the *examples only*. The prose that explains them is in `../OXIDE_API.md` and
+`../OPERATING.md`, which is exactly the trade that makes it 47% of the size.
+
+---
+
+## Regenerating
+
+These are build outputs, not hand-edited files. Re-capture and regenerate together —
+[`../README.md`](../README.md) § Provenance and refreshing has the procedure. **Never edit a file
+here by hand:** it will be silently overwritten on the next capture, and it would put the machine
+copy out of step with the markdown, which is the one thing this directory promises cannot happen.