Require real results in CLI, cache, and host regression tests

[AngriestBird]

Bottom line

Close all six assertion gaps from QA without changing production behavior.

• Check failed fix writes preserve bytes, exit 2, and count only successful edits.
• Isolate wrong-version and malformed-body sidecar rejection, including workspace cache misses.
• Require the activation API and specific CWTools command IDs.
• Check real webview node IDs and edges after raw initialization and restoration.
• Assert content from the same hover request measured against the existing latency limit.

Closes #717. Addresses the reported gaps in #520 and #693; their broader work remains open.

BLUF

[github-actions]

Coverage

Suite	% Lines	% Stmts	% Branch	% Funcs
Rust engine	🟢 91.9	🟢 91.9	⚪ -	🟢 93.8
Extension-host client	🟢 81.9	🟢 81.9	🟡 71.8	🟡 78.5
Node unit	🟡 77.6	🟡 77.0	🟡 74.1	🟡 76.2

_{🟢 ≥80% · 🟡 ≥50% · 🔴 <50% · ⚪ unavailable. Expand a section for file coverage and the full-report artifact.}

Rust engine details: 20 worst-covered files of 136

File	% Lines	% Stmts	% Branch	% Funcs
engine/crates/game/src/constants.rs	🟡 70.4	🟡 70.4	⚪ -	🟢 100.0
engine/crates/lsp/src/completion/mod.rs	🟡 74.3	🟡 74.3	⚪ -	🟡 71.0
engine/crates/rules/src/rules_converter/mod.rs	🟡 77.0	🟡 77.0	⚪ -	🟢 95.5
engine/crates/index/src/lib.rs	🟡 77.4	🟡 77.4	⚪ -	🟢 87.5
engine/crates/lsp/src/completion/builders.rs	🟡 77.5	🟡 77.5	⚪ -	🟢 93.3
engine/crates/validation/src/position.rs	🟡 77.8	🟡 77.8	⚪ -	🟢 90.6
engine/crates/lsp/src/config.rs	🟡 78.4	🟡 78.4	⚪ -	🟢 81.7
engine/crates/rules/src/rules_converter/subtypes.rs	🟢 81.9	🟢 81.9	⚪ -	🟢 92.3
engine/crates/lsp/src/navigation/structure.rs	🟢 82.5	🟢 82.5	⚪ -	🟢 81.8
engine/crates/lsp/src/server.rs	🟢 82.8	🟢 82.8	⚪ -	🟢 82.7
engine/crates/index/src/variables.rs	🟢 83.0	🟢 83.0	⚪ -	🟢 85.2
engine/crates/rules/src/rules_types.rs	🟢 83.8	🟢 83.8	⚪ -	🟡 74.7
engine/crates/cli/src/commands/discover.rs	🟢 84.2	🟢 84.2	⚪ -	🟢 100.0
engine/crates/cli/src/commands/cache.rs	🟢 84.5	🟢 84.5	⚪ -	🟢 100.0
engine/crates/index/src/path_match.rs	🟢 84.5	🟢 84.5	⚪ -	🟢 81.8
engine/crates/cli/src/commands/validate.rs	🟢 84.6	🟢 84.6	⚪ -	🟢 85.7
engine/crates/validation/src/rule_core/children.rs	🟢 84.6	🟢 84.6	⚪ -	🟢 97.2
engine/crates/lsp/src/format.rs	🟢 84.7	🟢 84.7	⚪ -	🟢 96.0
engine/crates/lsp/src/cursor.rs	🟢 85.0	🟢 85.0	⚪ -	🟢 90.0
engine/crates/game/src/scope_engine/engine.rs	🟢 85.0	🟢 85.0	⚪ -	🟢 87.0

_{Full report is in the rust-coverage artifact.}

Extension-host client details: 7 files

Measured labels: host. Source scope: extension/src/host, extension/src/common. Modules measured only by Vitest are excluded.

File	% Lines	% Stmts	% Branch	% Funcs
extension/src/host/lspClient.ts	🟡 66.5	🟡 66.5	🔴 44.4	🟡 57.1
extension/src/host/graphPanel.ts	🟢 84.0	🟢 84.0	🟢 80.5	🟢 100.0
extension/src/host/detectGame.ts	🟢 86.2	🟢 86.2	🔴 35.7	🟡 75.0
extension/src/host/extension.ts	🟢 86.2	🟢 86.2	🟡 68.2	🟢 80.0
extension/src/host/serverNotifications.ts	🟢 89.5	🟢 89.5	🟢 81.2	🟢 100.0
extension/src/host/fileExplorer.ts	🟢 91.6	🟢 91.6	🟢 90.2	🟡 77.8
extension/src/common/graphTypes.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟡 50.0

_{Full report is in the coverage-html artifact.}

Node unit details: 19 files

File	% Lines	% Stmts	% Branch	% Funcs
extension/src/webview/graph.ts	🟡 60.0	🟡 59.1	🔴 46.6	🟡 50.9
extension/src/host/commands.ts	🟡 67.0	🟡 67.0	🟡 58.2	🟡 59.2
extension/src/host/rulesSetup.ts	🟡 70.1	🟡 70.1	🟡 59.6	🟡 75.0
extension/src/host/documentLanguage.ts	🟢 90.3	🟢 84.0	🟡 63.3	🟢 90.0
extension/src/host/rulesManifest.ts	🟢 91.0	🟢 90.0	🟢 86.0	🟢 92.3
extension/src/host/diagnosticsSignature.ts	🟢 94.1	🟢 94.4	🟡 68.8	🟢 100.0
extension/src/host/commandProgress.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 90.0
extension/src/host/engine.ts	🟢 100.0	🟢 98.1	🟢 92.6	🟢 100.0
extension/src/host/executable.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/fileListSignature.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/fnv1a.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/focusTracking.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/games.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/graphAvailability.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/logger.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/reindexSettings.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/serverBlockedDialog.ts	🟢 100.0	🟢 100.0	🟢 100.0	🟢 100.0
extension/src/host/trustedPaths.ts	🟢 100.0	🟢 100.0	🟢 95.2	🟢 100.0
extension/src/host/watchedFiles.ts	🟢 100.0	🟢 100.0	🟢 83.3	🟢 100.0

_{Full report is in the coverage-node artifact.}