feat: track new LA click types via data-feature-name

[yodem]

⛔ DO NOT MERGE until initial_location_link is wired to the context chip

Three of the four labels from sc-44684 are implemented here. The fourth,
initial_location_link (pin-in-location), attaches to the context chip,
which does not exist on waiting-source. The tracking mechanism is already in
place, so wiring it is a one-line data-feature-name="initial_location_link"
once the chip lands. Merging before then ships an incomplete story.

Implements sc-44684 (3 of 4 labels).

New assistant_click feature_names via a dedicated data-feature-name
attribute, read by the host click tracker before the generic link/aria-label
logic (so anchors report clean labels without degrading accessibility):

• appetizer topics → related_topics_link
• thinking toggle → thinking_steps_toggle
• thinking ref link → thinking_steps_text_link
• deferred: initial_location_link (context chip — not on this base)

Validation: needs to be verified in cauldron before deploy (per story).

🤖 Generated with Claude Code

[gitvelocity-reviewer]

📊 Code Quality Score: 6/100

22 × 0.25 = 5.5, rounded to 6

Category	Score	Factors
🔭 Scope	5/20	3 files, single analytics subsystem, no new APIs or endpoints
🏗️ Architecture	4/20	Introduces data-feature-name convention for analytics priority; minor but deliberate architectural pattern
⚙️ Implementation	4/20	Simple DOM path traversal, attribute lookup, guard clause; removal of stopPropagation is a meaningful behavioral change
⚠️ Risk	5/20	Removing stopPropagation changes event propagation behavior; analytics changes are low-risk but propagation change could affect other handlers
✅ Quality	3/15	Good inline comments explaining intent and design decisions; no tests added for behavioral change
🔒 Perf / Security	1/5	Defensive typeof window.gtag guard is good practice

Was this score accurate? 👍 Yes · 👎 No

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