[T4rk1n]

Reverts #3947: plotly-cloud goes back to being installed only with dash[cloud], not by default.

plotly-cloud is not on conda-forge, so with it in install.txt the conda-forge dash package can't be built for 4.5.0 (the feedstock's pip check fails). Dash already handles it being missing: dash.py falls back to the Plotly Cloud placeholder button, and the plotly command prints an install hint.

• Removed plotly-cloud from requirements/install.txt (still in requirements/cloud.txt)
• The plotly command hint points at pip install dash[cloud] again
• Kept the Make plotly-cloud a default install dependency #3947 CHANGELOG line (it shipped in 4.5.0rc0/rc1) and added a Changed entry for the move back
• Added tests/unit/test_plotly_cli.py for the hint and the install requirements; both fail on dev and pass here

Checked: a fresh install of the branch doesn't pull plotly-cloud, and a dash_duo app without it installed renders with no console errors and shows the Plotly Cloud placeholder in the debug menu.

[github-actions]

Dash performance benchmarks

✅ all within thresholds

	scenario	metric	p90 (ms)	median	growth	baseline p90	note
✅	callback_chain	chain_ms	317.4	309.3	0.92x	499.1
✅	callback_chain	graph_ms	1.5	1.5	1.0x	2.4
✅	callback_fanout	fanout_ms	62.5	59.9	0.96x	92.5
✅	deep_nesting	render_ms	42.1	38.9	1.21x	56.8
✅	full_children_replace	replace_ms	4292.7	1545.6	18.95x	4697.1
✅	initial_render_large	render_ms	449.1	429.5	0.94x	694.4
✅	initial_render_small	render_ms	77.5	70.0	0.89x	104.0
✅	patch_append_nested	append_ms	106.8	76.1	2.56x	192.3
✅	patch_append_toplevel	append_ms	103.2	66.9	2.47x	140.2
✅	patch_scalar_update_large	update_ms	130.0	115.8	1.0x	202.9
✅	wildcard_all_resolve	wildcard_ms	222.6	209.9	0.96x	313.6
✅	wildcard_all_resolve	graph_ms	0.7	0.7	1.0x	1.3

growth = late-third / early-third per-op time; ~1 is flat, a large value means the per-op cost scales with accumulated state.

machine scale vs baseline: 0.73x - divided out of the baseline ratios so they compare like for like (the absolute warn/fail ceilings are left un-scaled); calibrated on initial_render_small.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud