Add a generic items_in_scope API to HIR that collects all visible items
in a given scope across the specified name domains. This follows the same
pattern as available_traits_in_scope and properly handles:
- Named imports
- Glob imports
- Unnamed/prelude imports
- Direct child items
- Parent scope items (recursively)

Add ScopeId::items_in_scope() as a convenient traversal-like method.

Rewrite completion handler to:
- Find the most specific scope at cursor position
- Use items_in_scope to get properly scoped completions
- Convert NameRes items to appropriate CompletionItem kinds

This fixes completion showing random unrelated symbols and provides
context-aware suggestions that respect lexical scope.

- Set insert_text, insert_text_format, and insert_text_mode to prevent
  unwanted text replacement and indentation issues
- Detect when completion is triggered by '.' for future member access
  implementation
- Add TODO for member completion (needs proper public API for type members)

This fixes the issue where completion would replace existing text and
add extra indentation.

…ter names

Use top_mod.target_at() instead of reference_at() + target_at() so that
rename works when cursor is on a definition name, not just references.

- Add textDocument/implementation handler for traits and trait methods
  - On traits: navigates to all impl Trait blocks
  - On trait methods: navigates to all implementations of that method

- Fix trait method rename to also rename implementations
  - When renaming a trait method, all corresponding method definitions
    in impl blocks are also renamed

- Add generic_params() method to SymbolView in HIR semantic API so
  both LSIF and SCIP generators use the same traversal
- Extract index_generic_params_for() helper in SCIP to eliminate
  duplicated generic param indexing code
- Refactor index_unnamed_item_generic_params to use the shared helper
- Update LSIF to use SymbolView::generic_params() instead of manual
  scope_graph.children() filtering

When ingot config metadata doesn't have a name field, fall back to
kind-based names ("core", "std") instead of "unknown". This fixes
symbol identity mismatches where definitions use "unknown 0.0.0" but
cross-ingot references use the proper "core 0.1.0" package name.

Impl/ImplTrait blocks have no resolvable pretty_path, so item_symbol()
returns None and the child-indexing block is never reached. Meanwhile,
methods inside these blocks are skipped by items_dfs because their
parent is a container. This left method-level type params (e.g. T, U, F
in `impl Applicative for Result<E> { fn ap<T, U, F>(...) }`) unindexed.

Fix: after indexing an unnamed item's own generic params, also iterate
its children and index their generic params with synthetic parent
symbols. Add regression tests for impl block method type params and
builtin core ingot symbol identity.

collect_ingot_urls was treating workspace roots as single ingots because
containing_ingot found the workspace's fe.toml and created an Ingot with
no ingot metadata (workspace configs have no name/version). This produced
"unknown 0.0.0" symbols in all SCIP output for workspace doc generation.

Root cause: the function checked containing_ingot before checking whether
the fe.toml was a workspace config. Now it checks for [workspace] first
and expands to member URLs, only falling through to single-ingot mode
when no workspace config is found.

Also introduces generate_scip_with_root to accept workspace root for
relative path computation, ensuring SCIP document paths match the
display_file paths used by the doc extractor's source views. Unifies
enrichment so both file:// and builtin:// ingots go through
enrich_signatures_with_base.

The § anchor link was only visible on hover for impl blocks, method
items, and h2 headers. Now also visible for member-item (variants,
fields, etc.) and implementor-item elements.

Also fix double border on signature blocks containing fe-code-block
by suppressing the inner wrapper's border/margin/background.

The source toggle was inside the flex item-header, causing code blocks
to be constrained to the right side of the header row. Now the file:line
stays in the header as a static label, and the expandable source view
sits below as a full-width collapsible block capped at 70vh.

Signature blocks were wrapped in <pre class="signature"> around
<fe-code-block>, causing double borders since the shadow DOM wrapper
has its own border/background. Now fe-code-block gets the class
directly (e.g. class="signature") with no outer wrapper.

For inline contexts (member-header, code-header, implementor-sig),
use CSS custom properties (--fe-code-bg, --fe-code-border) which
inherit through shadow DOM boundaries, replacing the unreachable
descendant selectors that couldn't pierce the shadow root.

The file:line label now serves as the toggle summary for the source
view, instead of being in the header with a separate "Source" button
below. Clicking the file path expands the source code.

Line numbers were 0.8rem while code text was 0.875rem, causing them
to drift out of alignment over many lines. Both now use 0.875rem.

Both line numbers and code text now use 0.8rem (down from 0.875rem),
keeping them aligned while making source views visually smaller than
the surrounding documentation text. Tightened padding to match.

The item name (h1) and signature wrapper now show a subtle § link on
hover for easy deep-linking. Also tighten member-header gap to reduce
space between the § anchor and the member signature.

Reduce gap to 0.25rem and zero out anchor margin-right for
member-header, method-header, and implementor-item elements.

Move signature-wrapper anchor to left margin, remove gap properties
from member-header/method-header/implementor-item, and zero out
anchor margin-right for inline contexts so padding alone controls
spacing.

…e margin

- Move all § anchors (member-header, method-header, implementor-item,
  impl-header, h2, item-header h1, signature-wrapper) to absolute
  positioning at left: -1.25rem in the page padding
- Remove gap properties from inline flex containers; padding alone
  controls spacing
- Remove duplicate shadow-DOM-unreachable styles from styles.css;
  fe-highlight.css is now the single source of truth for code block
  internals
- Add --fe-code-size and --fe-code-line-height CSS custom properties
  for consistent theming
- Add explicit line-height on line-number spans to prevent drift

- Remove all absolute-positioning hacks from anchors; use simple
  inline flex-item approach with fixed 1rem width across all contexts
- Fix stray CSS brace that broke stylesheet parsing
- Remove duplicate position:relative from containers
- Fix line number / code drift: set font properties on <pre> directly
  and use inherit on <code> to prevent browser defaults from diverging
- Remove dead shadow-DOM-unreachable wrapper/gutter/code rules from
  styles.css

- Unify border-radius to 4px across impl-block, implementor-item,
  member-item, method-item
- Match padding across impl-block summary and inner items (0.375rem
  0.625rem)
- Add background/border-radius to method-item to match member-item
- Remove redundant summary/no-toggle padding overrides
- Remove signature-wrapper: main item signature is just a
  fe-code-block now (h1 anchor is sufficient)
- Add align-self: center and line-height: 1 to .anchor for vertical
  centering

- Move all § anchors to appear after content (not before) in member
  headers, impl headers, method headers, and implementor items
- Make .anchor a simple inline element with margin-left, no flex/width
  tricks
- Restore signature-wrapper for main item signature with border
  suppression on inner fe-code-block to prevent double border
- All anchors now use the same simple pattern: inline, after content,
  appear on hover

Anchors are now the last child in flex rows with margin-left: auto,
pushing them flush to the right edge.

Replace div with <a> so clicking navigates to the impl block.
Use baseline alignment for signature flex rows. Anchor sits
far-right via margin-left: auto.

- Collapse nested if blocks in extract.rs and scip_index.rs
- Use !is_empty() instead of len() >= 1
- Avoid owned string comparison in test
- Switch implementor arrow to ↪, remove bold weight