feat(dashboard,tui): consolidate 17 dashboard tabs → 9, 9 TUI tabs → 7 (#2627)

[rysweet]

Summary

The dashboard (and TUI) had accumulated too many tabs with adjacent/overlapping purposes. This PR inventories every tab, proposes a consolidation, and implements it — collapsing the dashboard from 17 → 9 tabs and the TUI from 9 → 7, onto a single shared taxonomy. No data is lost: every former standalone tab becomes a labelled sub-section (<h2 class="subsection">) inside its parent tab, and every retired top-level slug keeps working as a deep-link alias.

Closes #2627.

Inventory (before)

Dashboard (17): overview, goals, traces, logs, processes, memory, costs, chat, workboard, thinking, brain-failures, merge-decisions, pr-readiness, terminal, overseer, status, journal.

TUI (9): Overview, Goals, Engineers, Activity, Meeting, Stats, Status, Overseer, Journal.

Proposal → consolidated taxonomy

Nine canonical dashboard tabs; the TUI mirrors the same names/order and renders the seven whose data exists in the terminal (it omits the web-only Pull Requests and Resources — adding those would be new feature work, not consolidation). Overseer and Journal are owned by separate, recently-merged features and are carried through unchanged.

#	Canonical tab	Absorbs (dashboard)	Absorbs (TUI)	Sub-sections	In TUI?
1	Overview	overview, status	Overview, Status, Stats	Summary · Health · Stats	yes (1)
2	Goals	goals, workboard	Goals	Goals · Work Board	yes (2)
3	Activity	logs, traces, thinking, brain-failures	Activity	Logs · Traces · Thinking · Failures	yes (3)
4	Workers	processes, terminal	Engineers	Processes · Engineers · Terminal	yes (4)
5	Pull Requests	merge-decisions, pr-readiness	—	Merge Decisions · Readiness	no (web-only)
6	Resources	memory, costs	—	Memory · Costs	no (web-only)
7	Chat	chat	Meeting (renamed)	—	yes (5)
8	Overseer	overseer (unchanged)	Overseer (unchanged)	—	yes (6)
9	Journal	journal (unchanged)	Journal (unchanged)	—	yes (7)

Rationale

• Overview / Status / Stats all answered "is the system healthy right now?" from three angles → one tab with Summary (what the agent is doing), Health (system status, PRs, issues, cluster), Stats (the operational snapshot rollup).
• Logs / Traces / Thinking / Brain Failures were four flavours of "what has the agent been doing?" → one Activity tab.
• Processes / Terminal (plus the TUI's Engineers view) are all "the workers running on this host" → Workers.
• Merge Decisions / PR Readiness are two views of the same PR pipeline → Pull Requests.
• Memory / Costs are both "resources the agent consumes/produces" → Resources.
• Meeting → Chat: the TUI label now matches the dashboard's Chat tab (the underlying meeting backend is unchanged).
• No tab is named "Bridge" (binding constraint).

Data preservation & deep-links

• Absorbed panels keep their exact markup and element ids; only the wrapping tab changed and their old <h1 class="page-h1"> became <h2 class="subsection"> (so each tab still owns exactly one page <h1>).

• A client-side TAB_ALIASES allowlist maps every retired slug to its parent tab. resolveHashTab() validates location.hash against ^[a-z-]+$, resolves the alias, scrolls to a section-<slug> anchor, and falls back to Overview on any unknown/malformed hash — the hash is never concatenated into a DOM selector, so a crafted #hash can't inject markup.

  #status → Overview, #workboard → Goals, #logs|#traces|#thinking|#brain-failures → Activity, #processes|#terminal → Workers, #merge-decisions|#pr-readiness → Pull Requests, #memory|#costs → Resources.

Concurrency

Rebased onto the latest origin/main, which already integrates the Journal refresh (#2618) and the enhanced Overseer detail (#2616/#2620). The consolidation keeps both as standalone tabs, untouched. Designed to merge last; the coordinated tab-registration files are tab_meta.rs, index_html/part_00.rs/part_01.rs, and the TUI app.rs/tabs/mod.rs.

Tests

• Rust: tests_tab_meta.rs (canonical taxonomy, no retired top-level slugs, exactly nine page-h1s, sub-section headers, TAB_ALIASES), tests_routes_a/b.rs, TUI app.rs (ALL_TABS == 7, digits 1–7). Full cargo test --all-features green; cargo clippy --all-targets --all-features -- -D warnings clean; cargo fmt clean.
• Python tab-identity smoke test (test_tab_clarity.py): nine canonical slugs, retired-slug deep links resolve to their parent, unknown hash → Overview with no injection.
• Playwright specs updated for the new tab set (logs → Activity, thinking → Activity, workboard → Goals, terminal → Workers, merge-decisions/pr-readiness → Pull Requests).

The durable tab taxonomy and its invariants are documented in docs/dashboard.md (Tab Identity Contract + Canonical tab taxonomy + Deep links). No point-in-time snapshot doc is committed.

[github-actions]

📊 Coverage Summary

Generated by cargo llvm-cov --workspace --summary-only (nightly, excluding test files)

Module	Lines	Covered	Coverage
Total	140341	116828	83.2%

_{Coverage data from CI run. Test files matching tests?/ are excluded from line counts.}