Fix outdated MASM guidance in agent skills

Several [Protocol-owned agent skills](https://github.com/0xMiden/protocol/tree/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills) contain incorrect guidance. Following it can produce invalid MASM or misleading Rust.

- [`advice-provider-hygiene`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/advice-provider-hygiene/SKILL.md#L93-L98) asserts the operand stack after `adv.has_mapkey` and says a missing lookup supplies a default. The flag is on the advice stack and a missing `adv.push_mapval` key errors; add `adv_push` before the assertion and remove the default-value claim.
- [`cheap-masm-equivalents`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/cheap-masm-equivalents/SKILL.md#L37-L47) reverses `cdrop`'s stack order and selected value. Use `[c, b, a]`, selecting `b` when `c = 1` and `a` when `c = 0`.
- [`decouple-component-from-storage`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/decouple-component-from-storage/SKILL.md#L10-L19) says every reusable component must receive its slot. Component-owned named slots are deterministic; limit this rule to generic utilities operating on caller-selected slots.
- [`felt-construction`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/felt-construction/SKILL.md#L10-L17) says `Felt::new` truncates and uses `Felt::MODULUS`. `Felt::new` is checked and returns `Result`; use `Felt::ORDER` when proving the bound for `new_unchecked`.
- [`masm-inline-comments`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/masm-inline-comments/SKILL.md#L138-L148) treats an `Asset` as one word and shows the wrong remove/add flow. Track its `ASSET_ID` and `ASSET_VALUE` words separately and preserve the original asset before removal.
- [`masm-locals-over-globals`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/masm-locals-over-globals/SKILL.md#L7-L31) uses removed word-local mnemonics without declaring locals. Use the `_be` or `_le` forms and add `@locals`.
- [`masm-padding`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/masm-padding/SKILL.md#L124-L149) documents removed `debug.*` instructions and a nonexistent `--debug` mode, while its [note script example](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/masm-padding/SKILL.md#L44-L52) is a `begin` program. Use `miden::core::debug` event procedures, account for their cycles, and represent note scripts as `@note_script` public procedures.
- [`u32-assert-before-u32-ops`](https://github.com/0xMiden/protocol/blob/07608d5bb9c50bdf27c14126d50c5a61322f4984/.claude/skills/u32-assert-before-u32-ops/SKILL.md#L10-L38) uses nonexistent `u32assert4` and `u32add` names and overstates which instructions require valid-u32 inputs. Use `u32assertw` and an explicit add mode such as `u32wrapping_add`; do not require prior assertions for `u32test`, `u32testw`, `u32cast`, or `u32split`.

The fix should update only these eight skill docs. No Protocol runtime behavior needs to change.