fix(plugins): honor plugin enable/disable without corrupting cordis.patch.yml

[yukitakasama]

What

Fixes #28 — toggling a plugin's enable/disable switch in instance settings showed a new state but had no effect after restart, and disabling a plugin mounted via - insert: could even corrupt the profile's cordis.patch.yml.

Root cause

The cordis.patch.yml editor used a flat line scan (set_disabled_row, read_disabled_ids, strip_cordis_rows):

1. Insert-mounted plugins (installed from the market / tgz): disabling matched the child - id: row and deleted that line, collapsing insert: from an array into an object. dsh's applyEntryPatches then threw a spread error on the un-iterable value, so the profile failed to boot.
2. Bundle-provided / top-level plugins: the appended - id: <id> + disabled: true override could target an entry the user layer never references, which the loader skips — so the plugin kept running.
3. read_disabled_ids scanned the same way, so the UI reported "disabled" while dsh still ran the plugin.

Fix

Reworked the three editors to be block-aware:

• disabled: true is added/removed on the matched entry's own row — both a plain top-level - id: entry and an - insert: block's child are recognized; the insert wrapper itself is never touched.
• Direct-child indentation is tracked, so a disabled: inside a plugin's own config: mapping (e.g. an MCP server option) is never mistaken for a plugin-level toggle.
• Bundle-provided entries (no row in this document) are disabled by appending a - id: + disabled: true override and re-enabled by dropping it — matching the loader's "bundle layers first, then the user layer" composition.
• Everything else is preserved byte-for-byte: comments, !!js scalars, unrelated entries, blank separators, and the [] placeholder of an empty document.

Verification

• cargo fmt --all -- --check clean
• cargo clippy --workspace --all-targets --locked -- -D warnings clean
• cargo test --workspace --locked: 95 passed, 0 failed
• 5 new regression tests cover: real profile shape (multiple insert blocks + a plain override), in-block toggling, bundle override round-trip, [] placeholder restore, and ignoring disabled: under config:

Tested against a real dsh-tui/cordis.patch.yml: after the fix the disabled plugin's own row carries disabled: true, the YAML still parses, and dsh's applyEntryPatches reports the plugin as disabled.

[Gu-ZT]

感谢这个 PR——问题定位准确，block-aware 重写方向正确，修掉了一个真实且严重的损坏 bug（已对照 dsh loader 源码 applyEntryPatches 验证：insert 塌陷后 data.push(...insert) 对不可迭代值 spread → profile 无法启动；顶层 entry 误删 id 行会把 config 行孤立进前一个 entry）。但探针测试实证了两个残余 bug，本次 request changes（修复都很小）：

阻塞项

1. [HIGH] 写入路径：插件自身 config: 内含 disabled: 键时，禁用操作静默无效

plugins.rs set_disabled_row 的子行扫描中（约 L1353），tl.strip_prefix("disabled:") 分支没有像 has_other（L1356）那样要求 indent_of(line) == t.child_indent。插件 config 里嵌套的 disabled: true|false（MCP server 类配置很常见）会置上 has_disabled/disabled_on，导致禁用路径既不 insert 也不 flip → 文件不变、开关无效——恰好复现 issue #28 的原始症状（开关显示变了但实际没生效）。读路径修了这类误报，写路径漏了。

修法：给该分支加上 child_indent 守卫，并补一个写路径回归测试（禁用 config 内含 disabled 键的插件）。

2. [MED] 读路径：entry 级 disabled: true 位于 config: 块之后时被漏读

disabled_ids 中 inside_config 的关闭条件要求 ind < current_child_indent（约 L958-964），但同级键正好位于 current_child_indent，所以 entry 内 inside_config 永不关闭：- id: x → config: → a: 1 → disabled: true（合法 YAML）会把 x 报为启用，UI 误报——正是本 PR 要修的 bug 类别。虽然本工具写入时把 disabled: 放在 config: 之前（读写自洽），但手改文件会踩中。

修法：非 disabled 键出现在 ind <= inside_config（或 == current_child_indent）时关闭 inside_config，补读路径测试。

3. [LOW] 裸 id: 在任意深度都会重置 current_id

约 L916 丢掉了旧版的无缩守卫：config: 内嵌套的 id:（如 MCP server 配置的 server: {id: fake, …}）会重置 current_id/inside_config，其后更深处的 disabled: true 会误报一个伪造 id。建议恢复缩进守卫。

非阻塞小项

• CRLF 文件经任何编辑后被归一为 LF（lines() + join("\n")），「byte-for-byte」的说法对 CRLF 不成立；
• 启用无匹配行时 L1309 提前返回 raw.trim_end() + "\n"，绕过了 replace_placeholder——空 patch 文件会得到 "\n" 而非其余代码依赖的 []\n 占位；
• 追加 override 时 id 不加引号（含空格/: 的 id 会产出非法 YAML——实践中 cordis id 是 slug，可接受）；
• 剥离 - insert: 的唯一子项后会留下空 insert 壳（合法 YAML、loader no-op，纯外观）；
• PR 描述称新增 5 个测试，实为 4 个（[] 占位恢复测试是既有用例）。

验证情况

• cargo fmt --check 干净；PR 自身测试 95 passed / 0 failed；
• 上述 Bug 1/2/3 均以临时探针测试实证复现（已按要求移除）；
• 分支基于 #34 合入前的 main，但仅改 plugins.rs，与 main 无冲突，rebase 非必需。

鉴于 insert 塌陷是数据损坏级 bug，修完 1-3 后应尽快合入。