refactor(params)!: flatten [params.page] to [params], snake_case keys, more page-level params support (#805)

* refactor(params)!: snake_case config + eliminate params.page + use .Param

BREAKING CHANGE: All params keys renamed from camelCase to snake_case,
[params.page] section eliminated (moved to [params] level), and users
must update their hugo.toml and front matter accordingly.

Key changes:
- All camelCase config keys → snake_case (e.g., defaultTheme → default_theme)
- [params.page] flat keys and sub-sections moved to [params] level
- Removed function/params.html (manual merge), replaced with Hugo .Param
- New function/param.html partial for page-level section params with
  shorthand boolean support and site defaults merging
- New function/camel-case.html for string conversion
- snake2camel.html renamed to camel-case-keys.html
- New function/get-cover.html for cover image resolution
- Deprecation warnings in detection-deprecated.html for old config keys
- Front matter only params (subtitle, featured_image, password, repost,
  weight, message) use .Params.xxx instead of .Param
- Page-level sections use param.html partial
- Simplified patch.html (siteTime only) and init/index.html

Refs: camel-case-keys.html#29 (planned v1.0 breaking change)

* refactor(params)!: move params.link to page-level, simplify link guard

- Move [params.link] and [params.link.guard] to page-level section
- link.html: .Page optional, use param.html when available for
  page-level override, fall back to site config without .Page
- Remove $guardConfig variable, use $config.guard directly
- Remove unnecessary .Page from callers that don't need page override
- friends.html: use param.html for link guard instead of link_guard

* refactor(params)!: move image/codeblock/json_viewer/filetree to page-level

- Move [params.image], [params.codeblock], [params.json_viewer],
  [params.filetree] to page-level sub-sections
- Templates use param.html for merged config (page override + site defaults)
- image.html: .Page optional, falls back to site config without .Page
- Add v1- prefix to all deprecation warnidf IDs
- Fix camelCase key access in image.html (blackList, cacheRemote)
- Fix Hugo-lowered camelCase keys in code-block-wrapper.html
- Add deprecation warnings for codeblock camelCase Markdown attributes
- Add deprecation warnings for file-tree camelCase Markdown attributes
- Update render-codeblock-toggle.html for snake_case attribute names

* style: standardize @param comment style across all HTML templates

- PascalCase types: {string} → {String}, {boolean} → {Boolean},
  {int} → {Int}, {map} → {Map}, {array} → {Array}
- Add missing ` - ` separator between param name and description
- Remove extra alignment spaces between type and param name

* refactor(params)!: move params.mermaid to page-level, extract gen/ templates

- Move [params.mermaid] to page-level sub-sections
- Mermaid config injected into window.config (per-page override support)
- mermaid.ts reads config from window.config.mermaid instead of parameter
- Create _partials/gen/ directory for JS content generators
- Move mermaid-bootstrap.html from plugin/ to gen/
- Extract window.config JS generation into gen/config.html
- mermaid.html uses param.html for wrapper config

* refactor(params)!: consolidate link_to_* into params.post_link section

- Move link_to_markdown/source/edit/report/vscode into [params.post_link]
- Rename keys: markdown, source, edit, report (bool), editor (string)
- editor defaults to "vscode", supports "trae" etc. via protocol template
- footer.html uses .Param "post_link" for all link toggles
- Remove link_to_* from deprecated keys list

* fix: add fallback for deprecated camelCase attributes and expand deprecation warnings

- render-codeblock-file-tree.html: folderSlash attribute fallback
- render-codeblock-toggle.html: lineNosToggler/lineWrapToggler fallback + warnings
- code-block-wrapper.html: maxShownLines/wrapperClass fallback
- detection-deprecated.html: add nested key warnings for 13 sections
  (header, breadcrumb, navigation, watermark, busuanzi, image, mermaid,
  codeblock, filetree, math.katex, math.mathjax.options, post_summary, footer)
- detection-deprecated.html: add link_guard front matter deprecation warning

* fix(mermaid): fix rendering in hidden tab panels and neutral layer scheduling

- isRenderContextActive: check tab-panel visibility via getBoundingClientRect
  instead of panel.hidden (tab-container uses slot-based hiding, not hidden attr)
- bindTabContainerChanged: render neutral layers when switching tabs so
  print/fallback scenarios work correctly

apps/test/content/posts/file-tree-test/index.md

@@ -49,7 +49,7 @@ This article tests the **File Tree** shortcode functionality in the FixIt theme.
 
 #### YAML format
 
-{{< file-tree folderSlash=true >}}
+{{< file-tree folder_slash=true >}}
 - name: project-root
   type: dir
   children:
@@ -99,7 +99,7 @@ type = "file"
 
 TOML with folder slash and level 3:
 
-{{< file-tree file="data/example.toml" level=3 folderSlash=true />}}
+{{< file-tree file="data/example.toml" level=3 folder_slash=true />}}
 
 #### JSON format
 
@@ -107,7 +107,7 @@ TOML with folder slash and level 3:
 
 JSON with folder slash and level 2:
 
-{{< file-tree file="filetree/example.json" level=2 folderSlash=true />}}
+{{< file-tree file="filetree/example.json" level=2 folder_slash=true />}}
 
 #### YAML format
 
@@ -131,15 +131,15 @@ Trying the file not found case (should fallback to next mode):
 
 #### With folder slash
 
-{{< file-tree data="example" folderSlash=true />}}
+{{< file-tree data="example" folder_slash=true />}}
 
 #### With level and folder slash
 
-{{< file-tree data="example" level=2 folderSlash=true />}}
+{{< file-tree data="example" level=2 folder_slash=true />}}
 
 #### Collapsed with ignore
 
-{{< file-tree data="example" level=0 ignoreList="README.md" />}}
+{{< file-tree data="example" level=0 ignore_list="README.md" />}}
 
 ## Filesystem Mode
 
@@ -165,13 +165,13 @@ Trying the file not found case (should fallback to next mode):
 
 {{< file-tree "assets" 0 />}}
 
-{{< file-tree path="assets" level=2 folderSlash=true />}}
+{{< file-tree path="assets" level=2 folder_slash=true />}}
 
 {{< file-tree "assets" -1 />}}
 
 ### With ignore lists
 
-{{< file-tree ignoreList=".hugo_build.lock, public, resources, node_modules" level=2 folderSlash=true />}}
+{{< file-tree ignore_list=".hugo_build.lock, public, resources, node_modules" level=2 folder_slash=true />}}
 
 ### root not exist
 
@@ -220,7 +220,7 @@ type = "file"
 
 ### With parameters
 
-```file-tree {level=2 folderSlash=true ignoreList="config.local.js"}
+```file-tree {level=2 folder_slash=true ignore_list="config.local.js"}
 - name: project
   type: dir
   children:
@@ -242,7 +242,7 @@ type = "file"
 
 ### Fully expanded
 
-```file-tree {level=-1 folderSlash=true}
+```file-tree {level=-1 folder_slash=true}
 - name: backend
   type: dir
   children:

apps/test/content/posts/link-test.md

@@ -7,11 +7,12 @@ categories:
   - Markdown
 tags:
   - Link
-link_guard:
-  enable: true
-  # mode: redirect
-  allow_domains:
-    - demo.fixit.lruihao.cn
+link:
+  guard:
+    enable: true
+    # mode: redirect
+    allow_domains:
+      - demo.fixit.lruihao.cn
 ---
 
 This post validates link rendering paths in FixIt, including Markdown render hook and link shortcode modes.

apps/test/content/posts/mermaid-diagrams-test.md

@@ -9,6 +9,8 @@ categories:
 tags:
   - Mermaid
   - Diagrams
+mermaid:
+  zenuml: https://cdn.jsdelivr.net/npm/@mermaid-js/mermaid-zenuml/dist/mermaid-zenuml.esm.min.mjs
 ---
 
 The FixIt theme supports two ways to use Mermaid: code block syntax and shortcode syntax.

apps/test/hugo.toml

@@ -43,10 +43,12 @@ _merge = "shallow"
 
 [params]
 version = "1.0.X"
+collection_list = true
+collection_navigation = true
 
 [params.home.profile]
 enable = true
-avatarURL = "/images/fixit-test.png"
+avatar_url = "/images/fixit-test.png"
 
 [params.social]
 
@@ -60,15 +62,8 @@ weight = 1
 # for twitter cards
 # site = "hugo-fixit"
 
-[params.page]
-collectionList = true
-collectionNavigation = true
-
 [params.author]
 name = "Lruihao"
 email = ""
 link = "https://lruihao.cn"
 avatar = "https://lruihao.cn/images/avatar.jpg"
-
-[params.mermaid]
-zenuml = "https://cdn.jsdelivr.net/npm/@mermaid-js/mermaid-zenuml/dist/mermaid-zenuml.esm.min.mjs"