docs(work): map testing and editor northstars

Add repo-local northstars and ready slices for testing strategy, LSP/editor completion, and hemplate highlighting boundaries.

work/slices/SLICE-0006-lsp-completion-surface.md

@@ -0,0 +1,40 @@
+---
+id: SLICE-0006
+type: slice
+status: ready
+parent: NS-0002
+title: Complete context-aware hemplate completions
+refs:
+  - REQUIREMENTS.md
+  - docs/editor-support.md
+  - docs/hemplate-syntax.md
+  - hemx-lsp/src/main.rs
+---
+
+## Objective
+
+Make completion useful for the real hemplate surface: directives, dynamic attributes, and `data-hemx-*` facts should complete in context without inventing syntax.
+
+## Authority
+
+`docs/hemplate-syntax.md` defines the public syntax; `docs/editor-support.md` and `REQUIREMENTS.md` `diagnostics/006` require completions to support that surface while remaining subordinate to build validation.
+
+## Close when
+
+- Completion items cover `h-if`, `h-for`, `h-key`, `h-match`, `h-case`, `{+ +}`, `{+= =+}`, `+attr`, and known `data-hemx-*` authoring facts.
+- Tests prove context filters: directive completions in tag attributes, snippet/text completions in text positions, and no irrelevant completions inside quoted Rust expressions.
+- Completion docs/details point to the existing syntax docs rather than new invented rules.
+
+## Verification
+
+- `cargo test -p hemx-lsp`
+- Manual check if needed: request `textDocument/completion` against a fixture through the LSP test harness.
+
+## Non-goals
+
+- Do not add Rust type inference or project-wide symbol completion in this slice.
+- Do not make completion acceptance a build authority.
+
+## Evidence
+
+`hemx-lsp/src/main.rs` already exposes `completionProvider` and `hemplate_completion_items` anchors.