docs(agent-feedback): take over two docs gaps from the marko backlog

Author: DylanPiercey

agent-feedback/bugs.md

@@ -7,3 +7,9 @@ Out-of-scope defects noticed while working on something else. Format and rules:
 `docs/reference/core-tag.md` › `## <html-script> & <html-style>` | 2026-07-29 | impact:low | effort:low
 
 `docs/reference/native-tag.md` has two headings that slug to the same base: the `style=` heading under Enhanced Attributes and the `<style>` heading under Enhanced Tags. `github-slugger` resolves collisions in document order, so the attribute section (line 56) takes `#style` while the tag section (line 533) becomes `#style-1`. Both `./native-tag.md#style` links in `core-tag.md` mean the `<style>` tag but land the reader on the unrelated `style=` attribute. `#script` is unaffected, since the `<script>` heading is the only one slugging to it. Prefer renaming one heading over hardcoding `#style-1`, which would rot silently if heading order ever changed. Re-verify from the repo root: `node --input-type=module -e "import S from './node_modules/github-slugger/index.js'; const s = new S(); for (const h of ['class=','style=','Event Handlers','<script>','<style>']) console.log(h, '->', s.slug(h))"` prints `style= -> style` and `<style> -> style-1`.
+
+## Add `NaN` and `0n` to the values that drop a `style=` declaration
+
+`docs/reference/native-tag.md` › `### style=` | 2026-07-30 | impact:low | effort:low
+
+The `style=` section states "A declaration is dropped when its value is `false`, `null`, `undefined` or an empty string, but `0` is kept" (line 90), which reads as the complete set but omits `NaN` and bigint `0n`. Marko's runtime writes a declaration only when `value || value === 0` (`stringifyStyleObject` in the marko repo's `packages/runtime-tags/src/common/helpers.ts`, where a bigint never satisfies `0n === 0`), so `<div style={ "line-height": total / count }/>` with a `count` of `0` renders no `line-height` declaration at all rather than the ignored `line-height:NaN` the current wording promises, and a `0n` value disappears the same way while the equivalent attribute still writes `NaN` or `0`. `docs/reference/language.md` already lists all six values under [Skipped Values](./language.md#skipped-values) for dynamic text and contrasts them with skipped attributes, so the `style=` sentence should carry the same set and link there; the neighboring `class=` claim ("every falsy value drops the class") needs no change, since a class name is kept only when its value is truthy. Re-verify: `grep -n "A declaration is dropped" docs/reference/native-tag.md` lists four values against the six in `grep -n "renders nothing" docs/reference/language.md`, then run `pnpm run lint`.

agent-feedback/unclear.md

@@ -13,3 +13,9 @@ Things that were hard to understand, and what would have clarified them. Format
 `docs/reference/template.md` › `Template.mount(input, node, position?)` | 2026-07-19 | impact:low | effort:low
 
 The `Template.mount(input, node, position?)` parameter table lists a Default of `{}` for `input` and `"beforeend"` for `position` (both real defaults) but `undefined` for `node`, which reads as "node is optional and defaults to undefined". `node` is actually required: `packages/runtime-tags/index.d.ts` in the marko repo declares `mount(input, reference: Node, position?)` with `reference` non-optional, and `packages/runtime-tags/src/dom/template.ts` › `mount` defaults only `input = {}` while `reference` has no default and is dereferenced unconditionally (`parentNode = reference as ParentNode`), so `template.mount(input)` is a type error and throws at runtime. The doc's own examples always pass a node (`template.mount({}, document.body)`), confirming node is mandatory. Agents treat parameter tables as the machine-readable contract: an agent building a client mount or test harness reads "node: Default undefined", writes `template.mount(input)` expecting a detached mount, and burns a debug cycle on the type mismatch — or, working from the rendered doc without a type-check, ships code that crashes on the undefined reference. Replace the `undefined` cell with "required" (or split required params from defaulted ones) so the table agrees with the `reference: Node` signature. Re-verify: read the parameter table under the `Template.mount` heading.
+
+## Document when a `<script>` that reads a tag variable first runs
+
+`docs/reference/core-tag.md` › `## <script>` | 2026-07-30 | impact:med | effort:low
+
+The `<script>` section says the body "is executed first when the template has finished rendering and is mounted in the browser" (line 370) and re-runs when a referenced tag variable changes, which leaves source order as the only ordering a reader can infer between two `<script>` tags. Marko compiles a `<script>` that reads a tag variable into that variable's own setup, so it first runs when the variable initializes, ahead of an earlier-in-source `<script>` that reads nothing: given `<let/board=DEFAULT/>`, a first script that only assigns `board` from `localStorage`, and a second that reads `board` and writes it back, the second runs first with `DEFAULT` and overwrites the saved value before the restore reads it (compiled dom output puts the persist effect inside `_let(...)` while the restore stays a separate `$setup__script`). The page's own `<script=remember/>` example already persists `input.collapsed` to `sessionStorage` without saying when it first fires, so the rule belongs there, stated positively: reading a tag variable ties the effect to that variable's initialization. The paired restore-and-persist idiom belongs under `## <lifecycle>`, whose `onMount`/`onUpdate` handlers already model "set up once, then follow the value" and give `<script>` somewhere to link. Re-verify: `grep -n "finished rendering" docs/reference/core-tag.md` is the page's only ordering statement and `grep -rn "localStorage" docs/` returns nothing, so neither the rule nor the idiom is documented today; the clobber itself reproduces in the local playground (`pnpm run dev`).